Exercise induced ventricular tachycardia

Exercise induced ventricular tachycardia

ECG showing ventricular tachycardia occurring during a treadmill exercise test: The initiating beat is a ventricular ectopic beat with R on T phenomenon. It is a monomorphic tachycardia with negative QRS in V1 and positive QRS in leads II and V5. This could be a tachycardia originating from the right ventricular outflow tract (RVOT) as it has an LBBB pattern and an inferior axis. RVOT tachycardias are known to be induced by exercise [1,2]. They can respond to beta blocker therapy and are also amenable for radiofrequency catheter ablation. Some cases are resistant and can recur even after multiple ablations. Exercise induced ventricular tachycardia can also occur in catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited arrhythmogenic disorder. But in CPVT, it is often a bidirectional ventricular tachycardia with alternating beats having opposite polarity [3]. Exercise induced ventricular tachycardia has been reported in isolated ventricular non compaction as well [4].

The second strip is the continuation of the first strip where the tachycardia breaks, only to restart after two sinus beats. The exercise had been stopped soon after the tachycardia was noted. Ventricular tachycardia during exercise could also be due to myocardial ischemia. Often the tachycardia subsides on stopping the exercise, while an occasional person may need a direct current cardioversion or pharmacological cardioversion.

Tracing during recovery showing that the tachycardia has subsided, but ventricular ectopics occurring in a trigeminal pattern with an R on T phenomenon.

References

1. Palileo EV, Ashley WW, Swiryn S, Bauernfeind RA, Strasberg B, Petropoulos AT, Rosen KM. Exercise provocable right ventricular outflow tract tachycardia. Am Heart J. 1982 Aug;104(2 Pt 1):185-93.
   
2. Gangadharan V, Sharma D, Ramu V, Paul T. Too much exercise: right ventricular outflow tract tachycardia. Am J Med. 2014 Mar;127(3):205-8. 
3. Francis J, Sankar V, Nair VK, Priori SG. Catecholaminergic polymorphic ventricular tachycardia. Heart Rhythm. 2005 May;2(5):550-4.
4. Güvenç TS, Ilhan E, Alper AT, Eren M. Exercise-induced right ventricular outflow tract tachycardia in a patient with isolated left ventricular noncompaction. ISRN Cardiol. 2011;2011:729040.