[Association of an epsilon wave and syncope]

BACKGROUND

Epsilon waves, rarely observed in clinical practice, result from late potentials favoring the development of ventricular rhythm disorders by reentry.

CASE REPORT

A 53-year-old man with sequellar myocardial infarction experienced a syncope. The surface ECG recorded an epsilon wave. Programmed ventricular stimulation before and after anti-arrhythmia drugs triggered ventricular tachycardia which was hemodynamically poorly tolerated. A defibrillator was implanted and confirmed retrospectively the rhythmic origin of the syncope.

DISCUSSION

The association of an epsilon wave and syncope should guide the etiology search towards severe ventricular rhythm disorders such as ventricular tachycardia. An electophysiologic study is required in order to determine the appropriate therapy and thus help avoid possibly fatal recurrence.

[Combination of celiprolol and amiodarone in the treatment of recurrent ventricular tachycardia]

The combination of beta-blockers and amiodarone has been shown to be affective in the treatment of refractory chronic ventricular tachycardia. However, the possible induction of excessive sinus bradycardia can constitute a limitation to the use of this treatment. Celiprolol is a cardioselective beta-blocker with a partial beta-2 agonist activity and an alpha-2 blocking activity, with a minimal depressant effect on heart rate. It therefore seemed useful to evaluate this drug in combination with amiodarone in patients with chronic ventricular tachycardia refractory to amiodarone alone. Twelve men with age of 57 +/- 16 years (9 with a history of myocardial infarction) received 200 mg of celiprolol per day associated with an average of 2 grams of amiodarone per week. Failure of oral amiodarone alone was confirmed by "reloading" (1,200 mg per day for 4 days) in 11 patients. The mean left ventricular ejection fraction was 36 +/- 19%, and was < or = 30% in 5 patients. Three patients were classified as stage 3-4 of the NYHA functional classification. Episodes of tachycardia were paroxysmal in 10 patients and diurnal in 10 cases. The effects of treatment were evaluated by clinical examination, continuous electrocardiographic monitoring, stress test and endocavitary electrophysiological investigation. No patient developed cardiac decompensation or collapse during beta-blocker treatment. In one case, the dose of celiprolol had to be decreased to 100 mg per day because of hypotension. No proarrhythmic effect was observed. The sinus rate remained unchanged after addition of celiprolol to amiodarone (57 +/- 3 bpm before versus 56 +/- 4 bpm after). On the stress test, the exercise capacity was maintained and no tachyarrhythmia was induced. Right ventricular refractory periods were not modified by celiprolol (mean effective period 289 +/- 20 ms before versus 294 +/- 20 ms after). Following a hospital stay of 17 +/- 7 days, the beta-blocker was discontinued in 5 patients because of persistence of permanent tachycardia in 1 case, and because of inducibility of a tachycardia with the same frequency as before treatment in the other 4 cases. No sudden death or haemodynamically unstable recurrence of ventricular tachycardia were observed during follow-up over a period of 38 +/- 24 months (range: 2-55) of the 7 patients in whom treatment was considered to be effective. Only one patient presented a temporary and reversible deterioration of heart failure. The absence of excessive bradycardia was also observed during follow-up. In one patient, celiprolol was replaced by another antiarrhythmic due to the recrudescence of inducibility to programmed stimulation. Three patients developed a spontaneous recurrence of sustained monomorphie ventricular tachycardia, which was well tolerated. In conclusion, these results suggest that celiprolol in combination with amiodarone in the treatment of refractory chronic ventricular tachycardia is a valuable therapeutic option because of its good inotropic and particularly chronotropic safety. However, the efficacy of treatment must be evaluated by a stress test and by endocavitary electrophysiological investigation including programmed ventricular stimulation in every case.

[Ventricular tachycardia in a patient with rate-responsive cardiac pacemaker]

The authors report a case of syncopal ventricular tachycardia in a patient with a respiratory-dependent rate responsive pacemaker, followed-up for valvular heart disease with severe left ventricular dysfunction and sustained atrial and ventricular arrhythmias. The introduction of low dose betablocker therapy with reinforcement of the treatment of cardiac failure controlled the ventricular arrhythmia, after suppression of the data responsive function had been shown to be ineffective. The authors discuss the role of the rate responsive function in the triggering of the ventricular tachycardias.

[Mitral valvuloplasty during the 4th month of pregnancy. Fetal protection with a lead mantle]

A 27 year old woman who had undergone closed heart surgical commissurotomy 10 years previously, underwent percutaneous mitral valvuloplasty during the fourth month of her pregnancy. Despite significant valvular thickening with calcification, the balloon dilatation led to an increase in valve surface area from 1.1 to 2 cm2 with no complications and with relief of the pulmonary hypertension. Foetal protection against ionising radiation was assured by a lead mantle completely surrounding the patient's abdomen. This protection reduced irradiation of the pelvic region to 0.5 milliSievert which corresponds to 1/100 of the permitted irradiation of pregnant women professionally exposed to ionising radiation.

[Evaluation of the response to the ajmaline test in the diagnosis of paroxysmal atrioventricular blocks]

Between October 1973 and December 1981, 31 symptomatic patients who underwent pacemaker therapy on the results of a positive Ajmaline test alone, showing infrahisian AV block, were followed up clinically and electrocardiographically. The mean follow up from the date of implantation was 30 months. Two groups of patients were identified according to the results of electrophysiological investigations and clinical and electrocardiographic follow-up: --group I: 13 patients with either infrahisian AV block or an HV interval greater than or equal to 120 ms after Ajmaline; --group II: 18 patients with an HV interval less than 120 ms after Ajmaline. During follow-up, the 5 AV blocks observed out of the 7 documented at inhibition of the pacemaker and the only two cases of deterioration of the intraventricular conduction during sinus rhythm occurred in Group I. The only discriminating variable between the two groups before the implantation of a pacemaker was the response to the Ajmaline test. The difference of the results of the electrical outcome between the two groups was statistically significant (p less than 0,03). During the same study period this critical value was observed in 49 other patients with a basal HV greater than or equal to 70 ms. In this group, 20 developed infrahisian AV block after Ajmaline, 26 had a HV interval greater than or equal to 120 ms and only 3 cases had HV intervals of 100 ms. These results suggest that a HV interval greater than or equal to 120 ms after Ajmaline has the same significance as infrahisian block produced by the drug.

[Applications of a minicomputer in an electrocadiography department]

The wide potential of minicomputers and their versatility have modified the traditional image of the computer, allowing it to gain a real foothold in a cardiological service. Examples of some original programmes are: the automatic assessment of a pacemaker on the test bench, the formation of programmed impulses for electrocardiographic investigation, the analysis of arrhythmias by a histogram of the RR interval of frequency analysis, the recording of isochrones in pericardial cartography.

[Epicardial scintigraphy in 4 cases of ventricular tachycardia caused by reentry of blood after myocardial infarct. Origin of the tachycardia and surgical approach]

110 point cartography was carried out over the ventricular pericardium during sinus rhythm (SR) and during ventricular tachycardia (VT) in four patients whose infarctions were 15 days, 4 months, 4 years and 7 years previously, and in whom electrocardiographic investigation had suggested a ventricular reentry phenomenon. The macroscopical appearances of the heart at operation suggested that the infarct was situated along the left side in two cases, and in or along the septum in two others. Cartography in sinus rhythm showed that the onset of ventricular activity was compatable with a site of origin in the node/bundle of His. Cartography during VT showed up the epicentre of the abnormal impulses which were always situated outside the exit points and dependent upon the node/bundle of His system as demonstrated by cartography in sinus rhythm. Moreover, in at least two cases this was found to lie outside the infarcted area, in portions of the myocardium which could be considered as healthy. In one case it was found to lie along the anterior interventricular groove, facing the septal infarct. In two cases the arrhythmia will not recur, one having achieved this status bu simple ventriculotomy. The failures are reported in relation to the extent of the lesion anatomically, which may cause disorientation of the surgical approach, and make the results difficult to interpret.

[Epicardial scintigraphy in 4 cases of ventricular tachycardia caused by reentry of blood after myocardial infarct. Study of intra-ventricular conduction disorders in sinus rhythm and in tachycardia, and their relations to anatomical data]

Ventricular pericardial cartography in sinus rhythm (SR) and during ventricular tachycardia (VT) in four cases of myocardial infarction has yielded additional information in the study of conduction disorders in myocardial ischaemia: 1. The significant slowing of activity in SR as well as in VT is demonstrated by this direct method. It is associated with a diminution in amplitude of the pericardial potentials in the zones affected by the ischaemia; 2. Cartography during VT accentuates or reveals disorders of conduction which are slight or latent in SR; 3. Disorders of intra-ventricular conduction are found to be related either to segmental blocks on the branches of the bundle of His, or as focal blocks (peri-infarct block) on the left side, whose nature can be shown up even during VT; 4. Secondary activation of the myocardial fiber found to be related either to segmental blocks on the bundle of His during VT is demonstrated.

Effects of verapamil on regional myocardial blood flow and ST segment. Role of the induced bradycardia

The effects of verapamil on regional myocardial blood flow and on the ST segment were studied in both normal and ischemic regions in dogs with and without cardiac pacing. In the absence of cardiac pacing, verapamil (0.05 mg/kg/min/10 min) induced marked bradycardia, a drop in blood pressure and an increase in epicardial and endocardial flows both in normal and ischemic regions of the heart. However, in ischemic regions, redistribution was favorable since the endo/epi ratio increased from 0.46 to 0.61 (p less than 0.01) whereas this ratio did not vary in normal regions (0.94 vs. 0.92). This increase is accompanied by less marked ST segment elevation during coronary occlusion in dogs treated with verapamil. In dogs with cardiac pacing, administration of verapamil under the same conditions again induced a drop in blood pressure and, in normal regions only, a homogeneous but less marked increase in epicardial and endocardial flows, the endo/epi ratio varying from 0.94 to 0.98. In contrast, in ischemic regions, blood flow was not modified by verapamil, but the endo/epi ratio dropped from 0.46 to 0.31 (p less than 0.01), while the ST segment elevation observed did not differ from that recorded during the control occlusion. These results demonstrate the major role of verapamil-induced bradycardia in the anti-anginal affects of this drug.