One MCQ a day- 14.04.2015

Answer to the question on 13.04.2015:

Answer : A (Right ventricular outflow tract)


12-lead electrocardiographic (ECG) morphology helps in identifying the PVC origin

Left bundle branch block morphology with an inferior axis indicates an outflow tract origin of the PVCs, with a late precordial transition (>V3) pointing to an origin in the right ventricular outflow tract, and an early transition (V3) suggesting an origin from the aortic cusps, the left ventricular outflow tract, or the basal left ventricular epicardium.

Right bundle branch block PVC morphologies indicate a left ventricular origin, with positive concordance indicating a basal origin and a precordial transition to an R/S complex suggesting origin in the papillary muscle.

Intramural arrhythmias are more difficult to localize, and a specific pattern has not yet been described.


1. Baman TS, Ilg KJ, Gupta SK, et al: Mapping and ablation of epicardial idiopathic ventricular arrhythmias from within the coronary venous system.Circ Arrhythm Electrophysiol 3:274–279,2010.

2. Good E, Desjardins B, Jongnarangsin K, et al: Ventricular arrhythmias originating from a papillary muscle in patients without prior infarction: A comparison with fascicular arrhythmias. Heart Rhythm 5:1530–1537, 2008.
3. Yokokawa M, Good E, Chugh A, et al: Intramural idiopathic ventricular arrhythmias originating in the intraventricular septum: Mapping and ablation. Circ Arrhythm Electrophysiol 5:258–263, 2012.

MCQ 14.04.2015

Treatment to decrease or eliminate frequency of premature ventricular contractions (PVC) is indicated in all of the following cases except

A. PVC triggering VT/VF

B. Frequent PVC causing nonresponse to cardiac resynchronization therapy

C. Asymptomatic occasional PVC

D. Very frequent PVC (>24% of QRS complexes on holter monitoring)

See below for answers



Treatment to decrease or eliminate PVCs should be considered in patients when an expected benefit in terms of symptoms or cardiac function exists. The categories of patients who should undergo treatment that targets PVCs can be summarized as follows:
• Patients with PVCs believed to be causing or contributing to LV dysfunction or dilatation
• Patients with symptomatically limiting PVCs • Patients with VT or VF for which a PVC trigger can be identified
• Patients in whom response to cardiac resynchronization therapy is limited by frequent PVCs
• Patients in whom deterioration of LV function may be expected, such as those with very frequent PVCs (>24%), may also be considered for therapy to reduce PVCs

Although clinical data regarding the last category are not yet definitive, PVC frequency in this range has been shown to often result in LV dysfunction, and a decision must be made on an individual basis between close follow-up of cardiac function versus prophylactic treatment to eliminate the PVCs.

Answer : C

(Ref: Cardiac Electrophysiology: From Cell to Bedside: 6th edition. Page 810)

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

One MCQ a day: 13.04.2015

Answer to the question on 12.04.2015:

Answer : A


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 :


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


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


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)