Arrhythmia or Disorders of Heart Rhythm

Arrhythmias or disorders of heart rhythm are a group of diseases characterized by abnormality of heart beat. Our heart is expected to beat in a certain way. In an adult individual the heart normally beats 60 t0 100 times per minute, in a regular manner (that means a nearly constant interval between two beats ). There are some normal variations, like in children the heart beat is faster, in some healthy persons and trained athelets the heart beat can be slower, during sleep the heart beat is normally slower.

Definition of Arrhythmia:

Arrhythmia is defined as any deviation from this normal pattern of heart beat.

What are the types of Arrhythmia?

Heart rhythm disorders are basically of two types. When the Heart rate is abnormally high it is called TACHYCARDIA. When the heart rate is abnormally slow it is called BRADYCARDIA. There can be irregular heart beats even if the heart rate is between 60-100, those cases are also Arrhythmic.

What is the relation of arrhythmias to other heart diseases?

Arrhythmias can be divided into two types based on heart diseases

  1. Arrhythmias occurring in persons having no underlying structural heart disease are called- IDIOPATHIC ARRHYTHIMAS
  2. Arrhythmia also arise in persons who have underlying structural heart diseases.

What are the symptoms of Arrhythmia?

Arrhythmias due to slow heart rate (Bradycardia) commonly cause

  1. Lethargy
  2. Fatigue
  3. Palpitation
  4. Light headedness
  5. Syncope (Transient loss of consciousness followed by full recovery)
  6. Sudden death

Arrhythmias due to fast heart rate (Tachycardia) commonly produce symptoms of

  1. Palpitation
  2. Faintness and light headedness
  3. Syncope (Transient loss of consciousness followed by full recovery)
  4. Sudden death
  5. Reduced pumping capacity of heart and related symptoms
  6. Some arrhythmias like atrial fibrillation can produce abnormal clotting of blood inside heart which can migrate to brain to cause stroke and paralysis.

How serious are Arrhythmias?

Some arrhythmias are benign and non life threatening, but they cause troublesome symptoms of palpitation and skipped beats.

Some arrhythmias are life threatening and can cause even sudden death. It all depends on the origin and type of arrhythmias and any other underlying heart disease.

How to diagnose arrhythmia?

Arrhythmias are commonly diagnosed by

  • ECG
  • Holter monitoring
  • Sometimes long term monitoring like – event recorders, loop recorders etc.
  • In some case Cardiac Electrophysiological study is required to diagnose a rhythm disorder.

What are the treatments available?

  1. Some transient arrhythmias terminate on their own and don’t need any specific therapy
  2. Underlying cause needs to be treated like- drugs, electrolyte disturbances, etc
  3. Medicines are usually the first line treatment
  4. Catheter Ablation: It is a procedure done in cardiac cathlab where an arrhythmia is ablated commonly by application of radiofrequency energy inside the heart. It is a safe procedure with prospect for complete cure of the arrhythmia.

 

DR. ANUPAM JENA
CONSULTANT INTERVENTIONAL CARDIOLOGIST & ELECTROPHYSIOLOGIST
KALINGA INSTITUTE OF MEDICAL SCIENCES
BHUBANESWAR, ODISHA
INDIA
EMAIL: drjena@live.com

 

 

 

 

 

Cardiology MCQ – 14.05.2016


What is the most probable site of origin of the tachycardia in a patient with structurally normal heart ?

MA VT epicardial1. Right ventricular outflow tract

2. Mitral annular VT

3. Tricuspid annulus

4. Idiopathic left fascicular VT

Atrial septal defect and Pregnancy – Patient Information

What is atrial septal defect (ASD)

Atrial Septal defect is an abnormal communication between the upper two chambers of the heart namely left atrium and right atrium. Normally the left and right atrium are separated by the interatrial septum. So in atrial septal defect (ASD)  a part of the interatrial septum is missing. See the image below

Atrial Septal Defect

(Source : www.wikipedia.org)

In patients with ASD there is mixing of oxygenated blood of left side with venous blood on the right side.

Pregnancy Issues:

Patients with even a large unrepaired secundum atrial septal defect usually tolerate pregnancy without complications. In cases where the ASD has been closed either by surgery or by device, the course of pregnancy is similar to a normal female without heart disease, except when there are preexisting problems with heart rhythm or pulmonary hypertension.

Complications:

The complications include

1- Disorders of heart rhythm – e.g. Atrial fibrillation

2. Pulmonary hypertension – where there is increased pressure in the blood vessels of the lung.

3. Paradoxical embolism – Sometimes blood clots formed in the leg veins (increased chances in pregnant females) can pass through the defect in the heart and get lodged in the brain and can cause stroke .

Precautions:
  1. Elective closure of ASD before contemplating pregnancy is advisable
  2. Meticulous attention should be paid to the maternal leg veins, particularly during peridelivery, because deep venous thrombosis could precipitate a paradoxical embolus and stroke.
  3. In case of any complication like atrial fibrillation, pulmonary hypertension, close follow-up with a cardiologist is recommended.
Keywords: Congenital heart disease, pregnancy and heart disease, Patient information, atrial septal defect.

Xray chest showing thickened and calcified pericardium

Eggshell calcification of the heart in constrictive pericarditis

 Eggshell calcification of the heart in constrictive pericarditis

Rajesh Vijayvergiya, Ramalingam Vadivelu, Sachin Mahajan, Sandeep S Rana, Manphool Singhal

World J Cardiol 2015 September 26; 7(9): 579-582

43/M presented with dyspnoea on exertion NYHA class III since 6 months. No other positive history.

On Examination:

HR-100/min  BP- 100/64   JVP- elevated, 18 cm; prominent X and Y descent

CVS: S1 S2 normal, Pericardial knock +

CXR : Calcified pericardium seen. See image

Echo: Thick, calcified pericardium.   > 25%  respiratory variation of mitral inflow velocities . Significant LV diastolic dysfunction

 

 

 

 

 

 

 

 

post bt shunt seroma

Interesting image- Post BT shunt seroma- a rare complication

Indian Heart J. 2014 Mar-Apr;66(2):227-30.

Post Blalock-Taussig shunt mediastinal mass – a single shadow with two different destinies

Rohit MK1, Vadivelu R2, Khandelwal N3, Krishna S3.

One of the rare complications following BT shunt surgery is seroma formation. It usually is benign and  x ray chest will reveal a mediatinal mass (left upper). CT scan usually confirms the diagnosis. Usually managed conservatively.

Image description:

Axial contrast chest CT obtained in a helical mode. The sagittal oblique maximal intensity projection image shows a small hypodense lesion of fluid attenuation seen adjacent to the BT shunt. No calcification, enhancement, septae, air foci or solid component was seen. Features are consistent with a post operative seroma. Thin long arrow points BT shunt. Broader, short arrow points seroma

 

dilated aortic root

When to intervene in patients with bicuspid aortic valve and dilated aortic root or ascending aorta

Circulation – December 4, 2015

Surgery for Aortic Dilatation in Patients with Bicuspid Aortic Valves:

 A Statement of Clarification from the American College of Cardiology/ American Heart Association Task Force on Clinical Practice Guidelines

Intervention in Patients with BAV and Dilatation of the Aortic Root (Sinuses) or Ascending Aorta:

  1. Operative intervention to repair or replace the aortic root (sinuses) or replace the ascending aorta is indicated in asymptomatic patients with BAV if the diameter of the aortic root or ascending aorta is 5 cm or greater

 

  1. Operative intervention to repair or replace the aortic root (sinuses) or replace the ascending aorta is reasonable in asymptomatic patients with BAV if the diameter of the aortic root or ascending aorta is 0 cm or greater and an additional risk factor for dissection is present (eg, family history of aortic dissection or aortic growth rate ≥0.5 cm per year) or if the patient is at low surgical risk and the surgery is performed by an experienced aortic surgical team in a center with established expertise in these procedures

 

  1. Replacement of the ascending aorta is reasonable in patients with BAV undergoing AVR because of severe aortic stenosis or aortic regurgitation when the diameter of the ascending aorta is greater than 4.5 cm
Reversal of factor X a inhibition

New Drug : Andexanet Alfa- Reversal agent for Factor X a inhibitors

NEJM- Nov 2015 – ANNEXA-A and ANNEXA-R ClinicalTrials

As of now the major limiting factor with the use of novel anticoagulants is the absence of  reversal agents in case of bleeding complications.

To find a solution to this problem, a new drug has been recently tested in ANNEXA-A and ANNEXA-R trials. Andexanet alfa, a new drug designed to reverse factor X a inhibition.

In the trial, Andexanet alfa was given to apixaban and rivoraxaban administrated healthy volunteers. Within minutes of administration anti factor Xa activity was reduced by more than 90% without any toxic or serious thrombotic effects.

Approach to the management of Venous thromboembolism

Step 1 :Confirm PTE or DVT diagnosis

Step 2: Look for contraindications for full dose anticoagulation. If contraindications exist then insert IVC filter.

Step 3 : If no contraindication then look for impending venous gangrene (in case of DVT) or cardiopulmonary collapse (cardiogenic shock/ RV dysfunction in case of PTE). If yes then start thrombolysis

Thrombolysis for DVT:

Indications : Impending venous gangrene, symptom duration < 14 days and low risk of bleeding

Mode : a)Catheter directed thrombolysis (CDT) : Fluroscopy guided placement of multiside holed catheter (pigtail) into the thrombus segment and infusing alteplase for 1-3 days at a rate of 0.5 mg to 3 mg/hour (50 mg diluted in 50 ml of NS). CDT is superior to systemic anticoagulation alone because of reduced post thrombotic syndrome and reduced bleeding complications

b)Pharmacomechanical Catheter directed thrombolysis (PCDT)

PCDT uses either the “Power Pulse” or “isolated thrombolysis” techniques. Power Pulse employs the AngioJet rheolytic thrombectomy system (Bayer, Warrendale, PA) to deliver and disperse the thrombolytic agent by a powerful pulse-spray injection. After bathing the clot in the thrombolytic agent, the AngioJet catheter aspirates the softened thrombus fragments. Isolated thrombolysis uses the Trellis peripheral infusion system (Covidien, Mansfield, MA) to deliver the thrombolytic agent directly into the clot. The agent is then circulated within the clot by an oscillating wire.

Advantage of PCDT over CDT : Reduced dose and infusion duration of alteplase thereby reducing bleeding complications and better efficacy

Thrombolysis for PTE :

For PTE there is insufficient evidence to recommend thrombolysis via a pulmonary artery catheter rather than systemic thrombolysis

Systemic thrombolysis dose: Alteplase 100 mg (10 mg as iv bolus over 10 min f/b 90 mg in 100 ml of NS infused over 2 hours)

Step 4

If there is no evidence of impending gangrene or cardiopulmonary collapse then initiate systemic anticoagulation

Phases of anticoagulation treatment:

Initial phase0 to 10 days:

IV or SC unfractionated heparin/LMWH/Fondaparinux/Rivaroxaban/Apixaban

Long term phase- 10 days to 3 months

Vitamin K antagonist – warfarin/acitrom (target INR: 2-3.5)

Rivaroxaban/Apixaban/Edoxaban/Dabigatran/LMWH

Extended phase-3 months to indefinite 

Indictions for extended therapy- 1.unprovoked/recurrent VTE    2. Malignancy related VTE

Drugs :

Vitamin K antagonist – warfarin/acitrom (target INR: 2-3.5)

Rivaroxaban/Apixaban/Edoxaban/Dabigatran/LMWH

Newer agents : Rivaroxaban(15 mg bd)/Apixaban(10 mg bd)/Edoxaban/Dabigatran(110 or 150 mg bd)

Pros- No need for INR monitoring, non-inferior or slightly efficacious then warfarin/acitrom, lesser major bleeding rates

cons- costlier, lesser availability especially in developing countries and no specific reversal agents

Myocardial Infarction- Third Universal definition and classification

Definition of myocardial infarction

Criteria for acute myocardial infarction :

The term acute myocardial infarction (MI) should be used when there is evidence of myocardial necrosis in a clinical setting consistent with acute myocardial ischaemia. Under these conditions any one of the following criteria meets the diagnosis for MI:

Detection of a rise and/or fall of cardiac biomarker values [preferably cardiac troponin (cTn)] with at least one value above the 99th percentile upper reference limit (URL) and with at least one of the following:

  1. Symptoms of ischaemia.
  2. New or presumed new significant ST-segment–T wave (ST–T) changes or new left bundle branch block (LBBB).
  3. Development of pathological Q waves in the ECG.
  4. Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.
  5. Identification of an intracoronary thrombus by angiography or autopsy.

•Cardiac death with symptoms suggestive of myocardial ischaemia and presumed new ischaemic ECG changes or new LBBB, but death occurred before cardiac biomarkers were obtained,or before cardiac biomarker values would be increased.

• Percutaneous coronary intervention (PCI) related MI is arbitrarily defined by elevation of cTn values (>5 x 99th percentile URL) in patients with normal baseline values (≤99th percentileURL) or a rise of cTnvalues >20% if the baseline values are elevated and are stable or falling. Inaddition,either(i)symptoms suggestiveof myocardialischaemia or (ii) new ischaemic ECG changes or (iii) angiographicfindings consistent with a proceduralcomplication or (iv) imaging demonstration of new loss of viable myocardium or new regional wall motion abnormality are required.

• Stent thrombosis associated with MI when detected by coronary angiography or autopsy in the setting of myocardial ischaemia and with a rise and/or fall of cardiac biomarker values with at least one value above the 99th percentile URL.

• Coronary artery bypass grafting (CABG) related MI is arbitrarily defined by elevation of cardiac biomarker values (>10 x 99th percentile URL) in patients with normal baseline cTn values (≤99th percentile URL). In addition, either (i) new pathological Q waves or new LBBB,or (ii) angiographic documented new graft or new native coronary artery occlusion, or (iii) imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.

Criteria for prior myocardial infarction

Any one of the following criteria meets the diagnosis for prior MI:

• Pathological Q waves with or without symptoms in the absence of non-ischaemic causes. • Imaging evidence of a region of loss of viable myocardium that is thinned and fails to contract,in the absence of a non-ischaemic cause.

• Pathological findings of a prior MI

 UNIVERSAL CLASSIFICATION OF MYOCARDIAL INFARCTION

Type 1: Spontaneous myocardial infarction

Spontaneous myocardial infarction related to atherosclerotic plaque rupture, ulceration, fissuring, erosion, or dissection with resulting intraluminal thrombus in one or more of the coronary arteries leading to decreased myocardial blood flow or distal platelet emboli with ensuing myocyte necrosis. The patient may have underlying severe CAD but on occasion non-obstructive or no CAD.

Type 2: Myocardial infarction secondary to an ischaemic imbalance

In instances of myocardial injury with necrosis where a condition other than CAD contributes to an imbalance between myocardial oxygen supply and/or demand, e.g.coronary endothelial dysfunction, coronary artery spasm, coronary embolism, tachy-/brady-arrhythmias, anaemia, respiratory failure, hypotension, and hypertension with or without LVH.

Type 3: Myocardial infarction resulting in death when biomarker values are unavailable

Cardiac death with symptoms suggestive of myocardial ischaemia and presumed new ischaemic ECG changes or new LBBB, but death occurring before blood samples could be obtained, before cardiac biomarker could rise, or in rare cases cardiac biomarkers were not collected.

Type 4a: Myocardial infarction related to percutaneous coronary intervention (PCI)

Myocardial infarction associated with PCI is arbitrarily defined by elevation of cTn values >5 x 99th percentile URL in patients with normal baseline values (£99th percentile URL) or a rise of cTn values >20% if the baseline values are elevated and are stable or falling. In addition, either (i) symptoms suggestive of myocardial chaemia, or (ii) new ischaemic ECG changes or new LBBB, or (iii) angiographic loss of patency of a major coronary artery or a side branch or persistent slow- or no-flow or embolization, or (iv) imaging demonstration of new loss of viable myocardium or new regional wall motion abnormality are required.

Type 4b: Myocardial infarction related to stent thrombosis

Myocardial infarction associated with stent thrombosis is detected by coronary angiography or autopsy in the setting of myocardial ischaemia and with a rise and/ or fall of cardiac biomarkers values with at least one value above the 99th percentile URL.

Type 5: Myocardial infarction related to coronary artery bypass grafting (CABG)

Myocardial infarction associated with CABG is arbitrarily defined by elevation of cardiac biomarker values >10 x 99th percentile URL in patients with normal baseline cTn values (£99th percentile URL).In addition,either (i) new pathological Q waves or new LBBB,  or (ii) angiographic documented new graft or new native coronary artery occlusion, or (iii) imaging evidence of new loss of viable myocardium or new regional wall motion abnormality