Pathologic findings in a patient dying with ventricular tachycardia.

I’ this issue of Chest (see page 24), James and MacLean present the pathologic findings in a 17-year-old male athlete with recurrent syncope, documented ventricular tachycardia, and sudden cardiac death. The patient’s brother had a somewhat similar history and also died suddenly. Pathologic examination in the present case revealed some fetal dispersion of the A-V node, a right-sided His bundle, and evidence of inflammatory neuritis and ganglioneuritis (most prominent around the area of the sinus node). Before commenting upon the pathologic features described by James and MacLean, we would like to make some clinical observations that we feel are relevant to this case. Examination of the 12-lead electrocardiogram during ventricular tachycardia (kindly supplied to us by Drs. James and MacLean) revealed a wide QRS tachycardia (rate approximately 200 beats/mm) with a QRS of left bundle branch pattern. These findings were consistent with ventricular tachycardia originating from the right ventricle.’ In our experience, electrocardiographic prediction of the site of origin of ventricular tachycardia in the absence of chronic ischemic heart disease (based upon QRS morphology of ventricular tachycardia), is a reliable guide to the ventricle of origin (ventricle of origin diagnosed by endocardial and/or epicardial mapping).’ This is in contrast to prediction of site of origin of ventricular tachycardia occurring in ischemic heart disease, where electrocardiographic prediction is considerably less reliable.2 Assuming that the case reported by James and MacLean is in fact an example of recurrent right ventricular tachycardia, one can question whether this diagnosis has any special implications. Recently, Fontaine et have described a group of patients with “arrhythmogenic right ventricular dysplasia.” This group of patients has been afflicted with recurrent right ventricular tachycardia proved by epicardial mapping, and sometimes cured with surgical attack upon the site of origin of the dysrhythxnia. Characteristic features of “arrhythmogenic right ventricular dysplasia” include delayed activation of portions of the right ventricle (occasionally diagnosed from the routine surface electrocardiogram, more frequently diagnosed from the amplified and computer average surface electrocardiogram), and discernible with endocavitary and epicardial mapping of the right ventricle. Right ventricular angiography in this group of patients reveals localized or generalized right ventricular wall motion abnormality, and pathologic examination reveals dysplastic changes in the right ventricle.3-5 Arrhythmogenic right ventricular dysplasia appears to be related to Uhi’s disease, which is characterized by partial or complete absence of the myocardium of the right ventricle with replacement by fibroelastic and adipose tissue.6 We are currently examining the heart of a young woman who died with right ventricular tachycardia complicating Uhi’s disease.7 The patient of James and MacLean did not have arrhythmogenic right ventricular dysplasia or Uhl’s disease either clinically or pathologically. Our laboratories have been aware of a strong association of recurrent right ventricular tachycardia and absence of clinically manifest organic heart disease (as opposed to left ventricular tachycardia, where organic heart disease is the rule).”8’9 We have noted great variability in the clinical manifestations of recurrent right ventricular tachycardia without organic heart disease.9 Our patients have fallen into a number of categories including: 1) sporadic paroxysmal sustained ventricular tachycardlia (usually reentrant based upon electrophysiologic criteria); 2) repetitive, nonsustained ventricular tachycardia (usually not reentrant utilizing electrophysiologic criteria); and 3) exercise-provoked right ventricular tachycardia (not reentrant by electrophysiologic criteria, but inducible with catecholamine infusion). Based upon QRS morphology, we would classify the presently reported patient of James and MacLean as an example of recurrent right ventricular tachycardia without apparent complicating organic heart disease. The history of sudden death in the brother is probably clinically relevant and certainly intriguing.