Ventricular Arrythmia

Question 1

VT with QRS fusion during entrainment

PPI = VTCL +/- 30 ms

Answer 1

Yes: Outer Loop
No : Remote bystander

Question 2

VT with CF during entrainment

PPI = VTCL +/- 30 ms
or
S-QRS = EG-QRS +/- 20 ms

Answer 2

No: Adjacent Bystander
Yes: Circuit

Question 3

VT with CF during entrainment

YES
PPI = VTCL +/- 30 ms
or
S-QRS = EG-QRS +/- 20 ms

S-QRS/ VTCL (%) =

Answer 3

<30% = Exit
31-50% = Central
51 - 70% = Proximal
>70% = Inner Loop

Question 4

PVCs of outflow tract origin with an LBBB morphology include

Role of isoproterenol

Answer 4

Differential: idiopathic outflow PVC of right ventricular origin, early arrhythmogenic right ventricular cardiomyopathy (ARVC ) or sarcoidosis.

In a series of 412 consecutive patients with PVCs, high dose isoproterenol (40 mcg/min) induced bursts of multifocal PVCs in 32 of 35 patients with ARVC (91%) compared with 42 of 377 without ARVC (11%) . Positive predictive value was 43.2% for diagnosis of ARVC and negative predictive value 99.1%. Hence, isoproterenol testing is helpful in the early stages of ARVC diagnosis.