The majority of patients with recurrent sustained ventricular tachycardia have a history of ischemic coronary artery disease associated with previous infarction and aneurysm. The next largest group of patients have an underlying congestive or hypertrophic cardiomyopathy. The remainder have a primary electrical disorder (with or without a normal structural heart), valvular disorder, congenital heart disease (repaired or nonrepaired), metabolic disorder, or drug toxicity.
What presenting symptoms and features on physical exam may help to make the diagnosis of ventricular tachycardia?
The presenting symptoms of ventricular tachycardia in large part depend on the rate of the rhythm and the extent of underlying cardiac disease. The presenting symptoms can be modulated by coronary artery narrowing, carotid and peripheral vascular disease, ejection fraction, and even relative hydration of the patient. Concomitant medications also may play a role in the initial symptoms. Symptoms vary from minor palpitations, chest heaviness, and lightheadedness to frank syncope and cardiac arrest; most patients experience a constellation of symptoms between the two extremes.
The classic findings on physical exam depend on the interrelationship between atrial and ventricular contraction. If the patient is not capable of conducting an electrical impulse retrograde from the ventricle to the atrium, the classic findings of atrioventricular (AV) dissociation are present: variable intensity of the first heart sound, inconsistent relationship between the jugular a wave and the v wave, and occasional cannon a waves when the atrium and the ventricle contract simultaneously. Retrograde conduction is associated with a regularity to the cannon a waves, and the signs of AV dissociation are absent.