Electrocardiography results were used to assess diagnosis and evolution of arrhythmogenic right ventricular disease. The initial ECG presentation and long-term changes were analysed in 74 consecutive patients with symptomatic ventricular tachycardia and arrhythmogenic right ventricular disease. On first available tracings, a left axis deviation of the QRS was found in 18 patients. The QRS length in V1 was > or = 110 ms in 39 patients, an epsilon wave was present in 17, and a complete right bundle branch block in four patients. The T wave was negative in V1-V3 in 37 patients (50%). In 36 patients, long-term electrocardiographic follow-up of 9.5 +/- 3.2 years was available. During this period, ECG changes were observed in 20 patients (56%): negative T waves in 11 patients, a new left axis deviation in three, QRS enlargement in 13 (including eight right bundle branch block), right atrial hypertrophy in three, and paroxysmal or established atrial fibrillation in three. On studying all 110 ECG tracings (74 initial recordings +36 follow-up ECGs), we found a strong correlation between QRS or T wave changes and the length of follow-up after the first symptom; mean time interval between first ventricular tachycardia and ECG recording was significantly longer in patients with negative T waves in the right precordial leads, QRS enlargement, or left axis deviation, than in patients without such abnormalities. ECG abnormalities were more frequent at 10 year and 5 year follow-up than on initial tracings. A normal ECG was found in 40% of patients during the first year of follow-up, 8% at 5 years, and never later than the 6th year. In conclusion, electrocardiographic diagnosis of arrhythmogenic right ventricular disease may be difficult in the initial stage of the disease, since a normal ECG is found in up to 40% of patients. During the follow-up, progressive and characteristic ECG changes will occur. Arrhythmogenic right ventricular disease can be excluded if the ECG is found to be normal 6 years or later after a first ventricular tachycardia attack.

Six patients (5 men, 1 woman) with a history ranging from 3-16 years of resistant vagal atrial arrhythmias were treated by atrial pacing at a rate of 90/Min. These patients have been followed up for an average of 5.5 years (range 2-11 years) with favorable results. The arrhythmias were characterized by daily or weekly attacks of typical atrial flutter and atrial fibrillation occurring mainly or exclusively at night, at rest, or in the digestive periods in otherwise normal hearts of middle-aged patients (first attack between 25 and 54, mean 40). The arrhythmias were resistant to quinidine, and were usually aggravated by digitalis, beta-blockers and verapamil. Amiodarone is usually the only effective drug in this syndrome, but was not used before pacing in the 2 first cases, and was ineffective in the other 4 cases. Electrophysiologic studies confirmed the absence of sick sinus syndrome, and the close relationship between relative bradycardia and the onset of the arrhythmia. Atrial pacing alone totally controlled the arrhythmia in 1 patient; amiodarone was used in conjunction with pacing in 3 patients. In 1 patient the improvement was clear but incomplete, and in 1 patient permanent atrial fibrillation occurred shortly after pacemaker implantation.

Sixty-two Holter recordings of sudden death due to ventricular fibrillation (VF) were analysed by full disclosure and computerized processing. Thirteen sudden deaths were due to torsades de pointes in noncoronary subjects (11/13), related to quinidine-like drugs and/or hypokalaemia: they were always initiated by a long RR cycle due to a post-extrasystolic pause, and announced by a progressive decrease of mean heart rate (from 77.5 +/- 2.5 to 60.6 +/- 2.7 beats min-1, P less than 0.001), in the three preceding hours. The other cases occurred in coronary patients (45/49), with acceleration of ventricular tachycardia (VT), monomorphic in 24 cases, polymorphic in 13, the ventricular rate increasing from 220.6 +/- 55 to 241.5 +/- 69 beats min-1, rather than with primary VF (12 cases). A cardiac pause (RR cycle exceeding 125% of the mean five preceding cycles) was present in 22/49 cases immediately before the onset of VT/VF. The coupling interval of the extrasystole initiating VT/VF was shorter than the shortest value encountered before: 377.6 +/- 94.5 ms vs 421.4 +/- 92.3. The prematurity index (coupling interval/preceding RR cycle ratio) was lower in primary VF than in VT leading to VF. In the last hour preceding VF, ST changes were unusual (five cases), whereas heart rate increased from 82.8 +/- 20 to 92.0 +/- 26.7 beats min-1, (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Twenty-four hour ambulatory electrocardiographic tape recordings of 30 patients (16 men and 14 women, mean age 42 +/- 17 years) with repetitive monomorphic idiopathic ventricular tachycardia were analyzed using a new computerized system designed to study 15 RR cycles and mean heart rate of the 3 minutes preceding any defined event. The mean (+/- SD) number of events analyzed per patient in 24 hours was 610 +/- 483 for single premature ventricular complexes, 622 +/- 490 for couplets, 260 +/- 411 for runs of 3 complexes, 186 +/- 476 for runs of 4, 108 +/- 173 for runs of 5, 82 +/- 129 for runs of 6 to 10 and 83 +/- 116 for runs of more than 10 complexes. The heart rate was faster before runs of ventricular tachycardia than before isolated extrasystoles (p less than 0.01) and a positive linear correlation was observed between the mean preceding heart rate and the type of extrasystolic activity, the length of the runs increasing with increasing preceding heart rate (r = 0.98, p less than 0.001). A long RR interval just before the occurrence of runs was present in 77% of the cases (23 of 30) with or without an oscillatory pattern of RR intervals due to bigeminy or trigeminy, and the length of the runs correlated positively with the duration of this long preceding diastole (r = 0.90, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term prevention of atrial fibrillation is not constantly realized by single-site right atrial pacing, and the beneficial role of multisite atrial pacing is still being studied. Accordingly, we compared the effectiveness of dual site and single site atrial pacing in 83 patients (50 men, 33 women, aged 69 +/- 10 years), who received a DDD device for primary sinus node dysfunction or bradycardia with documented atrial fibrillation. Inclusion criteria for dual site pacing were a sinus P wave > or = 120 ms and at least two episodes of documented paroxysmal AF in the 6 months preceding implantation. Dual site atrial pacing (high right atrium-coronary sinus ostium) was performed in 30 cases, and was compared to 53 single site paced patients, 21 with a P wave > or = 120 ms and 32 with a P wave < 120 ms. The basic pacing rate was programmed at 68 +/- 4 beats/min (range 60-75 beats/min). Sinus P wave (133 +/- 20 vs 95 +/- 9 ms; P < 0.001), paced P wave (107 +/- 14 vs 99 +/- 15; P < 0.05), number of antiarrhythmic drugs used (2.4 +/- 1.2 vs 1.6 +/- 1.5, P < 0.05), and the duration of symptoms (8.1 +/- 4.5 vs 3.8 +/- 2.4 years; P < 0.001) were significantly higher in dual site patients. The other characteristics were similar. During the follow-up of 18 +/- 15 months (range 3-30 months), paroxysmal AF was documented in 33 patients. Among these patients, 13 developed permanent AF following at least one episode of paroxysmal AF. When comparing dual site patients and single site patients with a P wave duration > or = 120 ms, paroxysmal AF incidence was lower in the dual site group (9/30 patients vs 15/21 patients, P < 0.01), as well as permanent AF (1/30 patients vs 8/21 patients, P < 0.01). By contrast, comparison between dual site patients and the group of single site patients with a P wave duration < 120 ms did not evidence any significant differences in paroxysmal (9/30 patients vs 9/32 patients) and permanent (1/30 patients vs 4/32 patients) AF incidences. Dual site seems better able than single site atrial pacing to improve the natural history of patients with a prolonged P wave, reducing the incidence of paroxysmal and permanent AF. No benefit could be expected in patients with a normal P wave duration.