Tag Archives: medical students

One MCQ a day: 13.04.2015

Answer to the question on 12.04.2015:

Answer : A

Explanation:

The ECG is showing atrial fibrillation with fast ventricular rate. The important issue in this ECG is that the ventricular rate is extremely fast, reaching up to 300 bpm. AF with very fast ventricular rate is suggestive of conduction over bypass tracts. Patients with preexcited atrial fibrillation who are hemodynamically stable are to be treated with intravenous procainamide or ibutilide. Patients who present with hemodynamic instability should undergo urgent direct current cardioversion. So the right answer is intravenous procainamide. after management of the acute episode the patient should be advised to undergo electrophysiological study with ablation of the accessory pathway as definitive therapy.

Ref: Blomstrom-Lundqvist C, Scheinman MM, Aliot EM, et al: ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias—executive summary: A report of the American College of Cardiology/American Heart Association task force on practice guidelines and the European Society of Cardiology committee for practice guidelines (writing committee to develop guidelines for the management of patients with
supraventricular arrhythmias). Circulation 108:1871–1909, 2003.

MCQ 13.04.2015:

What is the site of origin of the premature ventricular contractions :

VPC-RVOT

A. Right ventricular outflow tract

B. Left ventricular outflow tract

C. Papillary muscle

D. Left ventricular basal epicardium

Answers please

I will put the explanation and answer tomorrow

Keywords: Cardiology review, Cardiology, Multiple choice questions, medical students, Electrophysiology

One MCQ a day – 12.04.2015

Answer to the question on 11.04.2015

Answer : D

localizing the AP

1. Left free-wall APs are associated with positive delta waves in lead V1 and negative delta
waves in leads I and aVL

2. The ECG in a patient with a manifest right-sided AP shows a negative delta wave in lead V1 and positive delta waves in leads I and aVL.

3. The polarity of the delta waves in leads III and aVF is helpful in localizing the AP on the AV annulus. Positive delta waves in these leads point to an insertion at the anterior, anterolateral, or lateral aspect of the tricuspid or mitral annulus. Negative delta waves in these leads are consistent with an insertion at the inferior aspect of the AV valves (e.g., posterior, posterolateral, or posteroseptal aspect of the tricuspid or mitral annulus)

4. For anteroseptal and midseptal accessory pathways, a few additional observations are helpful. Typically, a negative delta wave is present in lead V1 in patients with anteroseptal and midseptal accessory pathways. Septal accessory pathways may be distinguished
from right free-wall pathways if the precordial QRS transition (negative to positive) occurs at or before lead V3. If the transition occurs between V3 and V4, the amplitude of the delta
wave in lead II is examined. An amplitude of 1.0 mV or greater is consistent with a septal AP, whereas amplitude less than 1.0 mV suggests a right free wall connection. In a patient whose ECG is consistent with a posteroseptal AP, a steeply negative delta wave in lead II is suggestive of an epicardial connection.

(Ref: Cardiac Electrophysiology: From Cell to Bedside: 6th edition, Page : 758)

MCQ 12.04.2015

A 32 years old male patient presented to emergency with complains of palpitation for 30 mins. He has history of recurrent episodes of palpitation for last one year. On examination his pulse was variable, blood pressure was 100/70 mmHg. The ECG is shown below. Which is the initial drug of choice for this patient

WPW-AF

A. Intravenous procainamide

B. Intravenous adenosine

C. Intravenous diltiazem

D. Intravenous Verapamil

Keywords: Cardiology, Multiple choice questions, medical students, Electrophysiology

One MCQ a day – 11.04.2015

Answer to the question on 10.04.2015

Answer: B

Accessory pathways are anomalous bypass tracts composed of working myocardial cells. Most APs insert along the mitral or tricuspid valve and are referred to as AV accessory pathways. Approximately 60% of APs insert along the mitral valve and are referred to as left free-wall pathways. About 25% insert along the septal aspect of the tricuspid or mitral valve and are classified as septal pathways. The remaining 15% are right freewall pathways.

Occasionally one may encounter APs that do not insert along the AV valves. Examples include atriofascicular, nodoventricular, nodofascicular, and atrionodal pathways.

Atriofascicular pathways connect the right atrium to the distal ramifications of the right bundle branch and are capable of only anterograde conduction.

Nodoventricular and nodofascicular pathways connect the AV node to the right ventricular myocardium and the specialized conduction system, respectively.

Atriofascicular and nodoventricular/nodofascicular connections are also notable for their decremental conduction properties.

Atrionodal pathways are rare and connect the right atrial myocardium to the AV node.

(Ref: Cardiac Electrophysiology: From Cell to Bedside: 6th edition, Page : 755)

 

MCQ 11.04.2015

Q. Localize the accessory pathway (AP) from the ECG

ANTEROSEPTAL AP

A. Left free wall AP

B. Posteroseptal AP

C. Right free wall AP

D. Anteroseptal AP

Please post your answers as comments.

Keywords: Cardiology, Multiple choice questions, medical students, Electrophysiology

One MCQ a day – 10.04.2015

One Cardiology MCQ a day

I will  post one MCQ on cardiology per day and next day I will submit the answer. So lets test our knowledge on cardiology.

Q.  Which of the following statements about location of accessory pathways (AP) is correct?

A.  10% of APs  are left free-wall pathways, 80% are septal and 10-15% are right freewall     pathways

B. 60% of APs  are left free-wall pathways, about one-fourth are septal and 15% are right freewall  pathways

C.  60% of APs  are left free-wall pathways, about 10% are septal and 30% are right freewall  pathways

D.  40% of APs  are left free-wall pathways, about 15% are septal and 45% are right freewall  pathways

Answers please (Tomorrow I will post the answer)

Top 10 Cardiology Articles of the week

Top 10 Cardiology Articles of the week (02.03.2015-08.03.2015)

1. Low-Level Transcutaneous Electrical Vagus Nerve Stimulation (LLTS) Suppresses Atrial Fibrillation

Conclusion: LLTS suppresses AF and decreases inflammatory cytokines in patients with paroxysmal AF. The results support the emerging paradigm of neuromodulation to treat AF.

2. Implantable Cardioverter-Defibrillator Therapy in Brugada Syndrome:A 20-Year Single-Center Experience

Background: Patients with Brugada syndrome and aborted sudden cardiac death or syncope have higher risks for ventricular arrhythmias (VAs) and should undergo implantable cardioverter-defibrillator (ICD) placement. Device-based management of asymptomatic patients is controversial. ICD therapy is associated with high rates of inappropriate shocks and device-related complications.

Objectives: The objective of this study was to investigate clinical features, management, and long-term follow-up of ICD therapy in patients with Brugada syndrome.

Methods: Patients presenting with spontaneous or drug-induced Brugada type 1 electrocardiographic findings, who underwent ICD implantation and continuous follow-up at a single institution, were eligible for this study.

Results A total of 176 consecutive patients were included. During a mean follow-up period of 83.8 ± 57.3 months, spontaneous sustained VAs occurred in 30 patients (17%). Eight patients (4.5%) died. Appropriate ICD shocks occurred in 28 patients (15.9%), and 33 patients (18.7%) had inappropriate shocks. Electrical storm occurred in 4 subjects (2.3%). Twenty-eight patients (15.9%) experienced device-related complications. In multivariate Cox regression analysis, aborted sudden cardiac death and VA inducibility on electrophysiologic studies were independent predictors of appropriate shock occurrence.

Conclusions: ICD therapy was an effective strategy in Brugada syndrome, treating potentially lethal arrhythmias in 17% of patients during long-term follow-up. Appropriate shocks were significantly associated with the presence of aborted sudden cardiac death but also occurred in 13% of asymptomatic patients. Risk stratification by electrophysiologic study may identify asymptomatic patients at risk for arrhythmic events and could be helpful in investigating syncope not related to VAs. ICD placement is frequently associated with device-related complications, and rates of inappropriate shocks remain high regardless of careful device programming.

3.Evaluation and Treatment of Patients With Lower Extremity Peripheral Artery Disease

The lack of consistent definitions and nomenclature across clinical trials of novel devices, drugs, or biologics poses a significant barrier to accrual of knowledge in and across peripheral artery disease therapies and technologies. Recognizing this problem, the Peripheral Academic Research Consortium, together with the U.S. Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, has developed a series of pragmatic consensus definitions for patients being treated for peripheral artery disease affecting the lower extremities. These consensus definitions include the clinical presentation, anatomic depiction, interventional outcomes, surrogate imaging and physiological follow-up, and clinical outcomes of patients with lower-extremity peripheral artery disease. Consistent application of these definitions in clinical trials evaluating novel revascularization technologies should result in more efficient regulatory evaluation and best practice guidelines to inform clinical decisions in patients with lower extremity peripheral artery disease.

4. Long-Term Survival Benefit of Revascularization Compared With Medical Therapy in Patients With Coronary Chronic Total Occlusion and Well-Developed Collateral Circulation

Objectives: The purpose of this study was to compare the long-term clinical outcomes of patients with chronic total occlusion (CTO) and well-developed collateral circulation treated with revascularization versus medical therapy.

Background: Little is known about the clinical outcomes and optimal treatment strategies of CTO with well-developed collateral circulation.

Methods: 2,024 consecutive patients with at least 1 CTO detected on coronary angiogram were screened. Of these, data was analyzed from 738 patients with Rentrop 3 grade collateral circulation who were treated with medical therapy alone (n = 236), coronary artery bypass grafting (n = 170) or percutaneous coronary intervention (n = 332; 80.1% successful). Patients who underwent revascularization and medical therapy (revascularization group, n = 502) were compared with those who underwent medical therapy alone (medication group, n = 236) in terms of cardiac death and major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction, and repeat revascularization.

Results: During a median follow-up duration of 42 months, multivariate analysis revealed a significantly lower incidence of cardiac death (hazard ratio [HR]: 0.29; 95% confidence interval [CI]: 0.15 to 0.58; p < 0.01) and MACE (HR: 0.32; 95% CI: 0.21 to 0.49; p < 0.01) in the revascularization group compared with the medication group. After propensity score matching, the incidence of cardiac death (HR: 0.27; 95% CI: 0.09 to 0.80; p = 0.02) and MACE (HR: 0.44; 95% CI: 0.23 to 0.82; p = 0.01) were still significantly lower in the revascularization group than in the medication group.

Conclusions In patients with coronary CTO and well-developed collateral circulation, aggressive revascularization may reduce the risk of cardiac mortality and MACE.

5.Percutaneous Circulatory Assist Devices for High-Risk Coronary Intervention

A unifying definition of what constitutes high-risk percutaneous coronary intervention remains elusive. This reflects the existence of several recognized patient, anatomic, and procedural characteristics that, when combined, can contribute to elevating risk. The relative inability to withstand the adverse hemodynamic sequelae of dysrhythmia, transient episodes of ischemia-reperfusion injury, or distal embolization of atherogenic material associated with coronary intervention serve as a common thread to tie this patient cohort together. This enhanced susceptibility to catastrophic hemodynamic collapse has triggered the development of percutaneous cardiac assist devices such as the intra-aortic balloon pump, Impella (Abiomed Inc., Danvers, Massachusetts), TandemHeart (CardiacAssist, Inc., Pittsburgh, Pennsylvania), and extracorporeal membranous oxygenation to provide adjunctive mechanical circulatory support. In this state-of-the-art review, we discuss the physiology underpinning their application. Thereafter, we examine the results of several randomized multicenter trials investigating their use in high-risk coronary intervention to determine which patients would benefit most from their implantation and whether there is a signal to delineate whether they should be used in an elective pre-procedure, standby, rescue, or routine post-procedure fashion.

6.Porcelain Aorta: A Comprehensive Review

Calcification of the thoracic aorta is often associated with valvular and coronary calcification, reflecting an underlying atherosclerotic process. It has been found to be associated with an increased rate of mortality and cardiovascular disease. Porcelain aorta (PA) is extensive calcification of the ascending aorta or aortic arch that can be completely or near completely circumferential. This entity is rare in the general population, but it has an increasing incidence in older patients and in patients with coronary artery disease (CAD) or aortic stenosis (AS). The clinical relevance is based on the fact that it can complicate surgical aortic valve replacement (SAVR) for the treatment of severe AS by preventing safe access via the ascending aorta. PA is associated with increased morbidity and mortality, especially as a result of increased perioperative stroke risk. Recently, transcatheter aortic valve replacement (TAVR) has emerged as a less invasive and feasible treatment option in patients at high risk for conventional SAVR. In some series, ≈20% (5%–33%) of patients undergoing TAVR were diagnosed with PA. Inconsistencies in the definition and the use of different diagnostic modalities contribute to this wide range of PA prevalence. This article reviewed the available published data to seek a consistent, clinically relevant definition based on contemporary imaging, a firm understanding of the pathogenesis and associations, and the clinical implications of this disease entity.

7.Digoxin use in patients with atrial fibrillation and adverse cardiovascular outcomes: a retrospective analysis of the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF)

Conclusion: Digoxin treatment was associated with a significant increase in all-cause mortality, vascular death, and sudden death in patients with AF. This association was independent of other measured prognostic factors, and although residual confounding could account for these results, these data show the possibility of digoxin having these effects. A randomised trial of digoxin in treatment of AF patients with and without heart failure is needed.

8.Diagnosis of atrial fibrillation after stroke and transient ischaemic attack: a systematic review and meta-analysis

Background:Among patients with atrial fibrillation, the risk of stroke is highest for those with a history of stroke; however, oral anticoagulants can lower the risk of recurrent stroke by two-thirds. No consensus has been reached about how atrial fibrillation should be investigated in patients with stroke, and its prevalence after a stroke remains uncertain. The authors did a systematic review and meta-analysis to estimate the proportion of patients newly diagnosed with atrial fibrillation after four sequential phases of cardiac monitoring after a stroke or transient ischaemic attack.

Methods: The authors searched PubMed, Embase, and Scopus from 1980 to June 30, 2014 and included studies that provided the number of patients with ischaemic stroke or transient ischaemic attack who were newly diagnosed with atrial fibrillation. They stratified cardiac monitoring methods into four sequential phases of screening: phase 1 (emergency room) consisted of admission electrocardiogram (ECG); phase 2 (in hospital) comprised serial ECG, continuous inpatient ECG monitoring, continuous inpatient cardiac telemetry, and in-hospital Holter monitoring; phase 3 (first ambulatory period) consisted of ambulatory Holter; and phase 4 (second ambulatory period) consisted of mobile cardiac outpatient telemetry, external loop recording, and implantable loop recording. The primary endpoint was the proportion of patients newly diagnosed with atrial fibrillation for each method and each phase, and for the sequential combination of phases. For each method and each phase, they estimated the summary proportion of patients diagnosed with post-stroke atrial fibrillation using random-effects meta-analyses.

Findings:  The systematic review returned 28 290 studies, of which 50 studies (comprising 11 658 patients) met the criteria for inclusion in the meta-analyses. The summary proportion of patients diagnosed with post-stroke atrial fibrillation was 7·7% (95% CI 5·0–10·8) in phase 1, 5·1% (3·8–6·5) in phase 2, 10·7% (5·6–17·2) in phase 3, and 16·9% (13·0–21·2) in phase 4. The overall atrial fibrillation detection yield after all phases of sequential cardiac monitoring was 23·7% (95% CI 17·2–31·0).

Interpretation: By sequentially combining cardiac monitoring methods, atrial fibrillation might be newly detected in nearly a quarter of patients with stroke or transient ischaemic attack. The overall proportion of patients with stroke who are known to have atrial fibrillation seems to be higher than previously estimated. Accordingly, more patients could be treated with oral anticoagulants and more stroke recurrences prevented.

9.Comparative Outcomes of Catheter-Directed Thrombolysis Plus Anticoagulation Versus Anticoagulation Alone in the Treatment of Inferior Vena Caval Thrombosis

Conclusions—There has been a steady increase in the use of CDT in the treatment of patients with inferior vena cava thrombosis in the United States. This observational study showed no significant difference in mortality between CDT versus anticoagulation alone; however, the bleeding events and resource utilization were higher in the CDT group. Adequately powered randomized controlled trials are needed in this area.

10.Drug-eluting stents versus bare metal stents prior to noncardiac surgery

DES implantation was not associated with higher adverse events after NCS. Moreover, the incidence of adverse events following NCS was lower when NCS was performed >90 days post-DES implantation suggesting that it may not be necessary to wait until 12 months post PCI with DES before NCS.

Calculation of heart rate from ECG

Calculation of heart rate from ECG

In my last post I have enumerated the points for studying an ECG.

The first step is to check the calibration and paper speed. Then comes the calculation of heart rate. There are various methods of calculating the heart rate from ECG. We will discuss about the most commonly used and authentic methods of calculation.

ALL THESE METHODS ARE APPLICABLE FOR PAPER SPEED OF 25MM/SEC.

No.1 and 2 are applicable for a regular heart rhythm. No.3 is applicable for irregular heart rhythm

No.1: Calculate the number of large boxes

Figure 1

Figure 1

Count the number of large boxes between two consecutive R-R waves. 300 divided by the number of large boxes between two consecutive R-R waves is the heart rate. In figure 1 there are 3 large boxes between two consecutive R-R waves, so the heart rate is 300/3 =100/minute.

No.2: Calculate the number of small boxes

Count the number of small boxes between two consecutive R-R waves. 1500 divided by the number of small boxes between two consecutive R-R waves is the heart rate. In figure 1 there are 16 small boxes between two consecutive R-R waves, so the heart rate is 1500/16 = 94/min. This method is more accurate than the previous method.

No.3: Calculate the total number of R-waves in the rhythm strip

This method is applicable when the heart rate is irregular e.g. in patients with atrial fibrillation, frequent VPCs etc. At a paper speed of 25 mm/sec the duration of a 12-lead ECG is 10 seconds. So count the total number of R-waves in the rhythm strip (the long lead II at the bottom of the ECG ) and multiply it by 6 to get the heart rate. In the example shown below there are frequent VPCs.

2011.11.8The total number of R-waves is 12. So the heart rate is 12×6 = 72/min

I suggest you practice all the methods in the beginning so that after sometime you will be well habituated to use a method as needed.

Next week we will discuss about analyzing rhythm from ECG.

ECG-full

Simplest approach to reading the ECG. Part-1

APPROACH TO READING THE ECG

ECG or EKG (the electrocardiogram) has retained its role as the first and foremost investigations for many cardiovascular diseases. ECG is absolutely mandatory for diagnosis of heart rhythm and for myocardial ischemia. It has a prominent role in the diagnosis and management planning of a variety of cardiac diseases starting from heart failure and cardiomyopathy to valvular diseases and pericardial diseases.

Health care professionals are expected to be familiar with ECG. But to make sense of the variously shaped lines we need a few basic steps. Is article is part of a series of articles on ECG.

There is a systematic approach to reading the ECG. Medical students should always try to make a written report of the ECG according to the heading as listed below. Try to report as many ECGs as you get, and try to remember the systematic approach to ECG reading.

Now lets start with our ECG reading.

1. Speed – Paper speed is conventionally 25 mm/sec. It is normally written at the bottom of the Ecg.

2. Calibration – Vertically, the ECG graph measures the height (amplitude) of a given wave or deflection, as 10 mm (10 small boxes) equals 1 mV with standard calibration. Always check the calibration otherwise a false diagnosis of chamber enlargement or hypertrophy will be made or missed.

3. Rate

4. Rhythm

5. Axis

6. Loop (mainly in congenital heart disease)

7. P-wave

8. PR- interval

9. QRS complex

10. ST- segment

11. T-waves

12. QT- interval

13. U- Wave

14. Any other abnormal waves (like:- osborn wave, epsilon wave etc)

These 14 points when remembered and applied in the analysis of ECG will give the diagnosis in almost all cases.

We will further delineate each point in simple and clear terms in the subsequent posts.

Top 10 Cardiology Articles of the week

Top 10 Cardiology Articles of the week (17.11.14-23.11.14)

1. A Polypill Strategy to Improve Adherence:Results From the FOCUS Project
Compared with the 3 drugs given separately, the use of a polypill strategy met the                   primary endpoint for adherence for secondary prevention following an acute MI

2. Six-month versus 24-month dual antiplatelet therapy after implantation of drug eluting    stents in patients non-resistant to aspirin: ITALIC, a randomized multicenter trial 
The ITALIC trial showed that rates of bleeding and of thrombotic events were not significantly different according to 6- versus 24-month DAPT after PCI with new-generation DES in good aspirin responders.

3.  First-in-Man Transseptal Implantation of a “Surgical-Like” Mitral Valve Annuloplasty Device for Functional Mitral Regurgitation

4.  Pressure-Wire-Guided Percutaneous Transluminal Pulmonary Angioplasty

5.  AVOIDing Oxygen in Suspected STEMI Tied to Smaller Infarcts, Less Recurrent MI

6.  Percutaneous Left Atrial Appendage Closure vs Warfarin for Atrial Fibrillation. A Randomized Clinical Trial

7.  Meta-analysis Questions One-Size-Fits-All Anticoagulant Strategy in STEMI Patients

8.  Periprocedural Complications and Long-Term Outcome After Alcohol Septal Ablation Versus Surgical Myectomy in Hypertrophic Obstructive Cardiomyopathy

9.  Spontaneous Coronary Artery Dissection Revascularization Versus Conservative Therapy

10.  Surgical Treatment of Moderate Ischemic Mitral Regurgitation

PARADIGM-HF Trial

A new class of drug (Neprilysin inhibitor ) when combined with angiotensin receptor blocker , has been shown to be better than Enalapril.

Angiotensin–Neprilysin Inhibition versus Enalapril in Heart Failure — NEJM.

Implantable cardioverter defibrillator (ICD) – the others

Implantable cardioverter defibrillator (ICD) – the others

New ACC/AHA/HRS Expert consensus document for implantable cardioverter defibrillator (ICD) implantation in patients who are excluded or not well represented
in clinical trials.

A guideline has been published for ICD implantation. This new document is a good attempt at helping cardiologists in deciding about ICD.
There are some good points about the document.

Overview of the guideline:

1. The doument considers the published studies in ICD and makes recommendations.
2. Since the guideline considers only patients who are excluded or not well represented in clinical trials, there is no class of recommendations or level of evidence.
Rather there are categories like recommended, not recommended, can be done etc
3. Patients have been divided into different populations and recommendations are made for each patient population.

The broad categories considered are:

1. ICD Implantation in the Context of an Abnormal Troponin that Is Not Due to a Myocardial Infarction
2. ICD Implantation Within 40 Days of a Myocardial Infarction
3. ICD Implantation Within 90 Days of Revascularization
4. ICD Implantation <9 Months from the Initial Diagnosis of Nonischemic Cardiomyopathy

We will discuss the recommendations in each category

1. ICD Implantation in the Context of an Abnormal Troponin that Is Not Due to a Myocardial Infarction

First group of patients are those having elevated troponin levels but not fulfilling the  definition of MI (see other causes of elevated troponin e.g.kidney disease,
acute pulmonary embolus, heart failure, myocarditis, chest trauma, or tachyarrhythmia)and satisfying standard ICD indications for primary and
secondary prevention. ICD is recommended is such patients.
The idea is to define whether the elevated cardiac markers are due to MI or not. If not due to MI then go for ICD implatation early and no need to wait
for 40 days, like in a post MI setting.

2. ICD Implantation Within 40 Days of a Myocardial Infarction

 

1-Implantation of an ICD within the first 40 days following acute MI in patients with                       preexisting systolic ventricular dysfunction (who would have qualified for a
primary prevention ICD) is not recommended.
2-In patients who, within 40 days of an MI, require nonelective permanent pacing, who               also would meet primary prevention criteria for implantation of an ICD, and recovery of       left ventricular function is uncertain or not expected, implantation of an ICD  is                          recommended.
The basis of such recommendations has been explained by the writing group
“This reflects the fact that implantation of
a pacemaker or ICD is associated with some risk, especially
infection. If the likelihood that a patient requiring PPM implantation
early post-MI will ultimately require a second
procedure to extract the PPM and leads and replace it with
an ICD system 40 days later, it would seem inappropriate
not to implant an ICD rather than a PPM.”
3-Patients within 40 days of an MI who subsequently present sustained or hemodynamically significant ventricular tachyarrhythmias.

In this scenario the following recommendations are made
(i)In patients who, within 40 days of an MI, develop sustained (or hemodynamically significant) ventricular tachyarrhythmias >48 hours after an MI and
in the absence of ongoing ischemia, implantation of an ICD is recommended.

(ii)In patients who, within 40 days of an MI, develop sustained (or hemodynamically significant) VT >48 hours after an MI that can be treated by ablation,
implantation of an ICD can be useful.

(iii)In patients who, within 40 days of an MI, develop sustained (or hemodynamically significant) ventricular tachyarrhythmias where there is
clear evidence of an ischemic etiology with coronary anatomy amenable to revascularization (and appropriately treated), implantation
of an ICD is not recommended.
4- Patients within 40 days of MI who present with syncope that is thought to be due to ventricular arrhythmia – implantation of an ICD can be done.
In this recommendation quite a liberal one as there is no need to document ventricular arrhythmia. ICD can be done for suspected ventricular arrhythmia ( on the
basis of clinical history, documented NSVT or EP study). There are no studies that have specifically addressed whether ICD implantation is beneficial  in the setting of syncope thought to be due to a ventricular tachyarrhythmia in the first 40 days after MI. However, the consensus of the writing group is that syncope in the setting of a recent MI is a potentially serious issue, and ICD implantation can be useful if syncope is thought to be due to a ventricular tachyarrhythmia (by clinical history, documented NSVT, or EP study), regardless of timing in relationship to an MI (either <40 days or >40 days after MI).
5- Elective ICD replacement for battery depletion can be done in first 40 days after MI (in patients who have been previously implanted with ICD).
6- ICD implantation in patients within 40 days of an MI who have been listed for heart transplant or implanted with a left ventricular assist device is not recommended.

3. ICD Implantation Within 90 Days of Revascularization.

The ICD indications can be primary and secondary or patients requiring permanent pacing
1-ICD is recommended for primary prevention within 90 days of revascularization
a. In patients who have indication for ICD implantation for primary prevention of sudden cardiac death,and who have undergone revascularization
that is unlikely to result in an improvement in LVEF >0.35, and who are not within 40 days after an acute MI.
2-ICD is recommended for secondary prevention within 90 days of revascularization
a. In patients with abnormal left ventricular function and previous indication for ICD for            secondary prevention of sudden cardiac death (resuscitated from cardiac arrest due to        ventricular tachyarrhythmia) and have abnormal left ventricular function,
implantation of an ICD is recommended.
b. In patients with normal left ventricular function and previous indication for ICD for                  secondary prevention of sudden cardiac death  (resuscitated from cardiac arrest due to        ventricular tachyarrhythmia) that is unlikely related to myocardial ischemia/injury
c. ICD not indicated in patients whose cardiac arrest or VT/VF was due to acute myocardial        ischemia or injury.
3-ICD recommendations for patients with indication for permanent pacemaker

ICD is recommended in patients with indication for permanent  pacemaker + indication for ICD.
This indication is likely to come-up for further discussion in view of recent developments. The FDA has approved Medtronic CRT-D and CRT devices for patients with AV-block,NYHA I,II, III heart failure and LVEF<50% (based on data from BLOCK-HF trial)(http://www.medscape.com/viewarticle/823485).
So many of the patients with the above indication for ICD will receive CRT-D.

4-ICD is recommended in patients who develop  sustained VT/VF not related to myocardial ischemia ,syncope, patients needing pulse generator replacement, patients listed for heart transplant or implanted with ventricular assist devices, who are not within 40 days of acute myocardial infarction

4. ICD Implantation <9 Months from the Initial Diagnosis of Nonischemic Cardiomyopathy

ICD recommended in:
1-Implantation of an ICD for primary prevention is not recommended within the first 3 months after initial diagnosis of NICM.
2-If recovery of left ventricular function is unlikely, implantation of an ICD for primary prevention can be useful between 3 and 9 months after initial diagnosis of NICM.

3-ICD is indicated in patients having sustained VT/VF, syncope, indication for permanent pacing, listed for heart transplant, implanted with ventricular assist devices

Indications for putting an atrial lead:

1. In patients with symptomatic sinus node dysfunction, an atrial lead is recommended.
2. In patients with sinus bradycardia and/or AV conduction disturbances limiting the use and/or up-titration of necessary beta-blocker or other negative chronotropic drug therapy, an atrial lead is recommended.
3. In patients with sinus rhythm who have a documented second- or third-degree AV block, but who are not otherwise candidates for cardiac resynchronization therapy, an atrial lead is recommended.
4. In patients with bradycardia-induced or pause-dependent ventricular tachyarrhythmia (such as patients with long QT syndrome and torsades de pointes) an atrial lead can be useful.
5. In patients with a documented history of atrial arrhythmias (but not in permanent atrial fibrillation), an atrial lead may be considered.
6. In patients with hypertrophic cardiomyopathy and a significant resting or provocable left ventricular outflow tract gradient, an atrial lead may be considered.

Atrial lead not indicated in:

1. In patients with no documented history of atrial arrhythmias who have no other reason for requiring an atrial lead, an atrial lead is not recommended.
2. In patients with permanent or longstanding persistent atrial fibrillation in whom efforts to restore or maintain sinus rhythm are not planned, an atrial lead is not recommended.
3. In patients with conditions likely to result in VF (rather than monomorphic or polymorphic VT) without a bradycardia-induced or pause-dependent mechanism of
initiation and no other indication for an atrial lead, an atrial lead is not recommended. Conditions likely to result in VF – idiopathic ventricular fibrillation, Brugada syndrome, catecholaminergic polymorphous ventricular tachycardia, and short QT syndrome

This article adequately covers patients who really need an ICD, but have been excluded from trials. I have made a simplified version of the document which is easy to
understand. Your comments and questions are welcome

 

 

Note:

1. The diagnostic criteria for acute MI, established by the joint ESC/ACC/AHA/WHF Task  Force, are the following:

An appropriate rise and/or fall in cardiac biomarkers with at
least one value above the 99th percentile upper reference level, together with evidence of myocardial ischemia and with at least ONE of the following:
 1. Electrocardiographic evidence of new ischemia (ST
segment shift or development of left bundle branch
block [LBBB])
2.  Evolution of pathologic Q waves on the electrocardiogram
3.  Imaging evidence of new regional wall motion abnormality
or new loss of viable myocardium
4.  Ischemic symptoms
(J Am Coll Cardiol 2012;60:1581–98.)
2. BLOCK HF trial (N Engl J Med 2013;368:1585-93)