Arrhythmogenic dysplasia of the right ventricle. Description of a case

A 43 year old man was admitted to our Clinic because of recurrent episodes of palpitation. The electrocardiogram showed incomplete right bundle branch block, frequent ventricular extrasystoles with left bundle branch block morphology and negative T waves in the precordial leads. Two dimensional echocardiography showed marked right ventricular dilatation and right ventricular radionuclide angiography located the enlargment in the infundibulum. Arrhythmogenic right ventricular dysplasia was then suspected. Cardiac angiography excluded the other most common causes of right ventricular dilatation and confirmed the diagnosis. Arrhythmogenic right ventricular dysplasia should thus be regarded as a possible cause of ventricular arrhythmias of unknown etiology.     

Complex arrhythmias in a patient with predominantly right ventricular cardiomyopathy

A 23-year-old man presented with ventricular tachycardia. The electrocardiogram revealed right bundle branch block plus right axis deviation. It also showed frequent episodes of asystole, 2: 1 sinuatrial block and couplets of left bundle branch block morphology. Electrophysiologic study demonstrated sinuatrial entrance block, with an HV interval of 65 msec. It was also possible to induce sustained ventricular tachycardia of left bundle branch block pattern with normal QRS axis. Subsequent investigations were consistent with the diagnosis of right ventricular cardiomyopathy with mild left ventricular involvement.     

Right ventricular cardiomyopathy showing right bundle branch block and right precordial ST segment elevation

A 73-year-old man who had a family history of sudden death, experienced syncope. His electrocardiogram (ECG) presented right bundle branch block and right precordial ST segment elevation which are findings identical with those in Brugada syndrome. The cardiac MRI showed right ventricular mild dilatation, and endomyocardial biopsy revealed fatty replacement of myocardial fibers. Though no ventricular tachyarrhythmias were induced during an electrophysiologic test, the effects on ECG of antiarrhythmic agents and autonomic modulations were similar to those in Brugada syndrome. This case may suggest the relationship between Brugada syndrome and right ventricular cardiomyopathy.     

Positive T wave overshoot as a sign of ventricular enlargement

A consecutive series of 86 patients with an inverted T wave showing terminal positivity (overshoot) of a specific pattern in the resting electrocardiogram were studied. Patients with bundle branch block or electrocardiographic evidence of acute infarction and those taking digoxin or a similar drug were excluded. In 67 patients the heart was examined by echocardiography and in a further two by direct inspection. Sixty six of the 69 patients had an abnormal thickness of the left (or right) ventricle or a calculated left ventricular mass greater than 200 g. Seven of the patients examined by echocardiography had clinically pure ischaemic heart disease; all showed evidence of left ventricular enlargement. In only 39 of the 63 patients with anatomical evidence of left ventricular hypertrophy or dilatation did the electrocardiogram satisfy the standard voltage criterion of left ventricular hypertrophy. In the absence of acute infarction, bundle branch block, or digitalisation positive T wave overshoot of the pattern described is a sign of increased ventricular mass.     

Positive T wave overshoot as a sign of ventricular enlargement.

A consecutive series of 86 patients with an inverted T wave showing terminal positivity (overshoot) of a specific pattern in the resting electrocardiogram were studied. Patients with bundle branch block or electrocardiographic evidence of acute infarction and those taking digoxin or a similar drug were excluded. In 67 patients the heart was examined by echocardiography and in a further two by direct inspection. Sixty six of the 69 patients had an abnormal thickness of the left (or right) ventricle or a calculated left ventricular mass greater than 200 g. Seven of the patients examined by echocardiography had clinically pure ischaemic heart disease; all showed evidence of left ventricular enlargement. In only 39 of the 63 patients with anatomical evidence of left ventricular hypertrophy or dilatation did the electrocardiogram satisfy the standard voltage criterion of left ventricular hypertrophy. In the absence of acute infarction, bundle branch block, or digitalisation positive T wave overshoot of the pattern described is a sign of increased ventricular mass.     

Ventricular tachycardia of left bundle branch block configuration in patients with isolated right ventricular dilatation. Clinical and electrophysiological features.

Electrophysiological studies showed ventricular tachycardia in five patients (four male, one female) with isolated right ventricular dilatation. All had been asymptomatic before the onset of palpitation which had developed in adolescence or early adult life. Tachycardia had been associated with syncope in four patients, and three had been resuscitated from ventricular fibrillation before investigation. The electrocardiogram during ventricular tachycardia showed a left bundle branch block pattern, and endocardial mapping at electrophysiological study confirmed the right ventricular origin. The presenting tachycardia could be induced in all patients by programmed stimulation, and in three patients ventricular tachycardia of differing configuration could be induced, but the right ventricular origin and left bundle branch block pattern were maintained. In two patients ventricular tachycardia degenerated into ventricular fibrillation. Cineangiography, cross sectional echocardiography, and multigated radionuclide angiography confirmed the dilated abnormal right ventricle while indicating that left ventricular function was normal. On resting electrocardiograms T wave inversion over the right precordial leads was the sole abnormality. There were no signs of right heart failure and exercise tolerance was normal. Four patients have received maintenance treatment with antiarrhythmic drugs, and one had undergone operative mapping and ablative surgery. Thus ventricular tachycardia complicating right ventricular dilatation may be associated with serious symptoms and ventricular electrical instability; and in adults it may be suspected on clinical grounds by inverted T waves in the right precordial leads.     

Ventricular tachycardia of left bundle branch block configuration in patients with isolated right ventricular dilatation. Clinical and electrophysiological features

Electrophysiological studies showed ventricular tachycardia in five patients (four male, one female) with isolated right ventricular dilatation. All had been asymptomatic before the onset of palpitation which had developed in adolescence or early adult life. Tachycardia had been associated with syncope in four patients, and three had been resuscitated from ventricular fibrillation before investigation. The electrocardiogram during ventricular tachycardia showed a left bundle branch block pattern, and endocardial mapping at electrophysiological study confirmed the right ventricular origin. The presenting tachycardia could be induced in all patients by programmed stimulation, and in three patients ventricular tachycardia of differing configuration could be induced, but the right ventricular origin and left bundle branch block pattern were maintained. In two patients ventricular tachycardia degenerated into ventricular fibrillation. Cineangiography, cross sectional echocardiography, and multigated radionuclide angiography confirmed the dilated abnormal right ventricle while indicating that left ventricular function was normal. On resting electrocardiograms T wave inversion over the right precordial leads was the sole abnormality. There were no signs of right heart failure and exercise tolerance was normal. Four patients have received maintenance treatment with antiarrhythmic drugs, and one had undergone operative mapping and ablative surgery. Thus ventricular tachycardia complicating right ventricular dilatation may be associated with serious symptoms and ventricular electrical instability; and in adults it may be suspected on clinical grounds by inverted T waves in the right precordial leads.     

Transient unifascicular, bifasicular and trifascicular block: electrophysiologic correlations in a patient with rate-dependent left bundle branch block and transient right bundle branch block.

Correlations of the His to ventricular (H-V) conduction time were made with the surface electrocardiogram during normal intraventricular conduction, unifascicular block (right bundle branch block), bifascicular block (left bundle branch block) and trifascicular block (right and left bundle branch block) in a patient with rate-dependent left bundle branch block who had transient right bundle branch block during recording of the His bundle electrogram. The results provide a functional confirmation of the theory that a prolonged H-V time is a manifestation of trifascicular disease.     

Étude rétrospective monocentrique sur la prévalence et la signification du bloc de branche droit incomplet chez les jeunes sportifs de compétition en Tunisie

AimsFew studies have assessed the prevalence and significance of right bundle branch block in athletes. Aims of this study were to evaluate the prevalence of incomplete right bundle branch block and its correlation with the nature of sports practice and to compare the athlete with right bundle branch block and the one with a normal electrocardiogram.MethodsIt was a retrospective study of the electrocardiogram and echocardiography of competitive athletes recruited in the medical-sports center of SousseResultsA total of 554 athletes were included. Mean age was 16.1 ± 2.9 years and 69 % were male. The mean training duration was 5.8 hours per week. The prevalence of incomplete right bundle branch block was 13.9 % (77 cases). Endurance sports were practiced in 71.4 % of cases among subjects with right bundle branch block versus 55.4 % in the rest of the population (p < 0.001). The basal diameter of the right ventricle was larger in athletes with right bundle branch block compared to athletes without right bundle branch block: 28 ± 3.6 mm versus 24 ± 2.4 mm (p < 0.001).ConclusionsThe results of this study suggest that right bundle branch block is a marker of incomplete right ventricular remodeling. This remodeling represents a form of adaptation to sustained elevation of volumetric load observed mainly in endurance sports.     

Changes in ventricular depolarization in patients in sinus rhythm following closure of ventricular septal defect associated with atrioventricular discordance

Closing the ventricular septal defect in patients with atrioventricular discordance with sutures placed through the defect onto the morphologically right septal surface should avoid production of complete heart block. To discover whether this procedure otherwise affects conduction, standard electrocardiogram (ECG) were compared preoperatively and postoperatively in 11 such patients. Operation had lengthened the PR interval in one and shortened it in another. The QRS interval remained unchanged in 5 patients thought 2 of these showed minor changes in QRS configuration. Four patients showed QRS prolongation (increase greater than 20 msec) with delayed conduction towards the right ventricle and the initial QRS vector preserved, i.e., morphologically right bundle branch block. Two patients showed QRS prolongation with initial QRS vector alteration and delayed conduction towards the left ventricle, i.e., morphologically left bundle branch block. Repair through the morphologically left ventricle invariably caused bundle branch block. Repair through a right atriotomy caused bundle branch block in only 3 of 8 patients. Therefore closure of a ventricular septal defect by this method, particularly transatrially, need not affect conduction. Morphologically left ventriculotomy rarely if ever causes morphologically left bundle branch block. When present, morphologically right bundle branch block presumably results from interruption of the proximal right bundle.     

Electrocardiographic criteria of left ventricular hypertrophy in the presence of left bundle branch block

When left bundle branch block (LBBB) is present on the electrocardiogram, the diagnosis of left ventricular hypertrophy (LVH) may be difficult. The left ventricular mass in 70 patients with LBBB was estimated by echocardiography, and was compared to the QRS configuration on the electrocardiogram. We found that there was agreement between a monophasic R pattern in lead 1 or V6 (sensitivity 79.3%, 70.7%) and left ventricular hypertrophy. We suggest that a monophasic R pattern in L1 and V6 may provide a useful simple index of left ventricular hypertrophy in the presence of left bundle branch block.     

Incessant slow bundle branch reentrant ventricular tachycardia in a young patient with left ventricular noncompaction

A 15-year-old girl was admitted to the cardiology outpatient clinic due to mild palpitations and documented incessant slow ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern. The baseline electrocardiogram revealed first-degree atrioventricular block and intraventricular conduction defect. Transthoracic echocardiography showed prominent trabeculae and intertrabecular recesses suggesting left ventricular noncompaction (LVNC), which was confirmed by cardiac magnetic resonance imaging. During electrophysiological study, a sustained bundle branch reentrant VT with LBBB pattern and cycle length of 480 ms, similar to the clinical tachycardia, was easily and reproducibly inducible. As there was considerable risk of need for chronic ventricular pacing following right bundle ablation, no ablation was attempted and a cardioverter-defibrillator was implanted. To the best of our knowledge, no case reports of BBR-VT as the first manifestation of LVNC have been published. Furthermore, this is an extremely rare presentation of BBR-VT, which is usually a highly malignant arrhythmia.     

A case of tricuspid annular calcification]

A 76-year-old man was referred to our hospital with complaints of productive cough, dyspnea and peripheral cyanosis. The chest X-ray film indicated the pulmonary emphysema and acute bronchitis, but no abnormal intracardiac calcification. The electrocardiogram revealed a peaked P-wave, complete left bundle branch block, and ventricular premature contraction. Chest tomography demonstrated abnormal intracardiac calcium deposition in the right heart region. Two-dimensional echocardiography revealed the tricuspid annular calcification in the postero-lateral portion, showing a synchronous movement with tricuspid annular motion throughout the cardiac cycle. The size of calcification was 10 x 14 mm. The tricuspid valve showed no significant regurgitation. Left ventricular dilatation, associated with mild mitral regurgitation and impairment of systolic function (EF = 49%) was revealed by echocardiography. Serum examination revealed positive in Wassermann reaction. This case of tricuspid annular calcification might be caused by atherosclerotic degenerative change related to the aging process, or by an unknown mechanism related to pulmonary emphysema.     

Coexistent Wenckebach phenomenon in the distal branches of the specialized conduction system

A patient in whom Wenckebach phenomenon was observed to coexist in the three distal branches of the specialized ventricular conduction system, with an intermittent trifascicular block producing a second degree A-V block, is described. Surface electrocardiogram demonstrated the presence of this phenomenon in the right bundle branch (RBB) and the anterior division of the left bundle branch (LBB). Evidence of the presence of Wenckebach phenomenon in the remaining fascicle was provided by His bundle recording.     

A case of arrhythmogenic right ventricular dysplasia with prominent late potential

A case of arrhythmogenic right ventricular dysplasia with frequent episodes of ventricular tachycardia (VT) in a 57-year-old man is reported. His electrocardiogram showed a normal axis and inverted T waves in V1-V3 during sinus rhythm and a left bundle branch block pattern during VT. The VT could be terminated by either intravenous administration of lidocaine or procainamide or by cardioversion. Echocardiogram and right ventriculography showed reduced wall motion of the apex and infundibulum of the dilated right ventricle. No evidence of ischemic heart disease was found by left ventriculography, coronary arteriography and RI scintigraphy. A prominent late potential following the QRS complex was recorded by averaging and magnifying the surface electrocardiogram. The combination of oral mexiletine and disopyramide partially suppressed the VT attacks and relieved the subjective symptoms, however the late potential remained almost unchanged.     

Radiofrequency catheter ablation for treatment of bundle branch reentrant ventricular tachycardia: results and long-term follow-up

Seven of 120 consecutive patients with inducible sustained ventricular tachycardia (from September 1, 1988 to January 1, 1991) had bundle branch reentrant tachycardia and underwent percutaneous radiofrequency ablation of the right bundle branch. The seven patients had been unsuccessfully treated with a mean of 3 +/- 1 drugs. Four patients presented with syncope and three with aborted sudden death. The baseline electrocardiogram revealed a left bundle branch block pattern in three patients and an intraventricular conduction defect in four. The baseline HV interval was prolonged in each case (79 +/- 2 ms). With use of programmed ventricular extrastimuli, sustained bundle branch reentrant tachycardia was inducible in all patients at a mean cycle length of 283 +/- 17 ms (range 230 to 350). Bundle branch reentrant tachycardia characteristics included atrioventricular dissociation, a His deflection that preceded each QRS complex and spontaneous His to His variation that preceded changes in ventricular tachycardia cycle length. A quadripolar catheter was positioned across the tricuspid valve with the distal electrode tip of the catheter near the right bundle branch. One to three applications of continuous unmodulated radiofrequency current at 300 kHz between the distal electrode and a large posterior skin patch resulted in complete right bundle branch block in all patients, after which none had inducible bundle branch reentrant tachycardia on restudy. On restudy, three of the seven patients had ventricular tachycardia of myocardial origin (not bundle branch reentry). One patient required no therapy; drug or defibrillator therapy was used in the others.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathologic correlations in a case of complete heart block with split his potentials resulting from a stab wound of the heart

A 23 year old previously healthy man was stabbed in the anterior chest. This resulted in a ventricular septal defect and complete atrioventricular (A-V) block. The electrocardiogram revealed complete A-V block with a QRS pattern of right bundle branch block. His bundle recordings 26 days later revealed A-V dissociation with split His potentials (P-H₁ interval of 100 msec and H₂-V interval of 40 msec). During the study the escape QRS shifted from right to left bundle branch block with H₂ potentials still preceding each QRS interval with H₂-V intervals of 40 msec. A permanent pacemaker was implanted because of persistent congestive heart failure and bradycardia due to A-V block. The patient subsequently became asymptomatic. He died suddenly 3 $\text{1}\text{2}$ years later.Pathologically there were sizable openings in both the tricuspid and mitral valve substance and a ventricular septal defect involving the pars membranacea and part of the adjacent muscular septum. Serial sections of the conduction system revealed total destruction and fibrous replacement of the bifurcation and beginning of the right and left bundle branches and subtotal fibrous replacement of the branching bundle. Thus, the bifurcation of the bundle of His was totally absent at autopsy despite apparent electrophysiologic evidence of its existence 26 days after the stab wound. A possible explanation for this discrepancy is the subsequent fibrosis of the bifurcation produced by hemodynamic changes at the lower margin of the ventricular septal defect.     

An electro- and vectorcardiographic study of ventricular activation in scleroderma]

Electrical ventricular activation was studied by means of electrocardiogram and vectorcardiogram in 62 patients, 55 women and 7 men, affected by systemic sclerosis of average disease duration of 10.3 years. 45% of the patients showed the "diffused form" of the disease and 55% the "limited form". The vectorcardiogram showed some alterations of the ventricular activation in 55% of the recorded cases. The previous electrocardiogram found only 18%. The alterations, which are more frequent in the diffuse form than in the limited one, are the presence of loss of forces in septal, lateral or inferior or combined areas and intraventricular conduction disorders as complete and incomplete right bundle branch block, left anterior subdivision block, left posterior subdivision block, or combination between incomplete right bundle branch block and left anterior or posterior subdivision block. The vectorcardiogram was more sensitive than the electrocardiogram in showing loss of forces, also in patients with the limited form of systemic sclerosis, when the electrocardiogram was normal. Moreover the vectorcardiogram is helpful to identify left posterior subdivision block. The vectorcardiographic investigation seems to be a useful complement of the electrocardiogram especially for the identification of cases with myocardial involvement that is clinically silent.