[Anomalies of the T wave following treatment of complete chronic left branch block by massage of the carotid sinus or injection of adenosine triphosphate]. / Anomalies de l'onde T après effacement d'un bloc complet de la branche gauche d'allure chronique par massage du sinus carotidien ou injection d'adénosine triphosphorique.

We studied the T wave during normal conduction in 25 patients aged 42 to 81 years (average 62 +/- 5) during sinus rhythm and complete left bundle branch block which regressed transiently after carotid sinus massage (22 cases) or injection of adenosine triphosphate (5 cases). Six patients had angina pectoris; coronary arteriography in 3 of the other 19 patients was normal. The reversion to normal intraventricular conduction was obtained with a lengthening of the ventricular cycle in all patients. The T wave axis with narrow QRS complexes was between + 70 degrees and -140 degrees (normal T axis in 11/25 patients); in the horizontal plane, the T wave was negative in V2 in 4 patients, in V2-V4 in 12 patients, in V2-V6 in 7 patients and in V4 in 1 patient. The amplitude of inversion in V2 varied from 0.1 to 1.5 mV; there was no significant difference between the patients with angina (0.50 +/- 0.31) and the remainder (0.43 +/- 0.16). In normal conduction, the T wave changes were more common in the horizontal plane (24/25 patients: 96%) than in the frontal plane (14/25 patients, 56%). The high incidence of abnormalities of ventricular repolarisation after regression of complete left bundle branch block does not appear to be related to coronary artery disease. Another explanation is proposed because of the analogy with the changes observed after terminating right ventricular pacing and after regression of a Wolff-Parkinson-White syndrome. An abnormality of initial ventricular depolarisation--common to left bundle branch block, the Wolff syndrome and right ventricular pacing--could be responsible for these T wave changes during normal conduction.(ABSTRACT TRUNCATED AT 250 WORDS)

[Sinoatrial and intra-atrial conductive disorders. The value of recording the sinus node potential]. / Troubles conductifs sino-auriculaire et intra-auriculaire. Intérêt de l'enregistrement du potentiel sinusal.

Direct recording of the sinus node potential in the bipolar mode using two electrodes of a quadripolar recording catheter positioned in the region of the sinus node at the junction of the superior vena cava to the right atrium was performed in 24 patients. Asynchronous overdrive atrial pacing was carried out using Strauss 'technique. Pharmacological denervation was carried out using intravenous propranolol (0,02 mg/kg) and atropine (0,04 mg/kg) using Jose's technique. An intravenous injection of a bolus of 20 mg of ATP was given in 3 cases. The sinus potential was identified by morphological criteria and confirmed after carotid sinus compression and atrial extrastimuli to exclude artefacts, especially the end of ventricular repolarisation of the preceding complex. The sinoatrial conduction time measured directly under basal conditions was considered normal when within 80 to 150 ms. Direct measurement of the sinus potential in the diagnosis of sinus node dysfunction seems to be less useful than the indirect techniques. On the other hand, it does confirm the diagnosis of sinoatrial block: five cases of special interest are described; in four cases the degree of sinoatrial block was variable: a significant increase of sinoatrial conduction time under basal conditions in 1 case; paroxysmal 3rd degree sinoatrial block revealed by programmed atrial stimulation in 2 cases; 2nd degree 2/1 sinoatrial block after injection of ATP in which the direct sinoatrial conduction time and sinus node function had been considered to be normal (1 case).(ABSTRACT TRUNCATED AT 250 WORDS)

Wolff-Parkinson-White syndrome: T wave abnormalities during normal pathway conduction.

Forty-five patients with Wolff-Parkinson-White syndrome (WPW) were reviewed. The preexcitation using Boineau's classification was: right anterior (six patients), left lateral (nine patients), right posterior (15 patients) and left posterior (15 patients). Normal pathway conduction was observed to occur either spontaneously or after administration of ajmaline, procainamide, or by eye-ball pressure. Disappearance of preexcitation was associated with T wave abnormalities in 39 patients (86.6%). The orientation of the T spatial vector (SAT), after suppression of the WPW aspect, varied according to the site of ventricular preexcitation. In eight patients with left lateral ventricular preexcitation (LLVP), the frontal T wave axis was between +70 degrees and +120 degrees (mean +92 degrees) and the horizontal T wave axis was located in the left anterior quadrant. In the five patients with right anterior ventricular preexcitation (RAVP), the frontal axis was between + 40 degrees and - 10 degrees (mean + 26 degrees) and the horizontal axis was in the left posterior quadrant. The 26 cases with right posterior ventricular preexcitation (RPVP) and left posterior ventricular preexcitation (LPVP) had a frontal axis between - 10 degrees and - 70 degrees (mean -39 degrees) and the horizontal T wave axis in the left anterior quadrant. This study suggests that the T wave anomalies observed after suppression of the WPW aspect are in direct relation to the localization of the preexcitation according to Boineau's classification. The analogy between the abnormalities of the T wave and those which are observed after right ventricular pacing (VP) or after disappearance of left bundle branch block (LBBB) is discussed.

[Auricular fibrillation with ventricular tachycardia. Surgical section of a left lateral bundle of Kent]. / Fibrillation auriculaire à haute fréquence ventriculaire. Section chirurgicale d'un faisceau de Kent latéral gauche.

The authors report the case of a man of 22 years, with no previous cardiac history, in whom a Wolff-Parkinson-White syndrome was discovered during the course of this first episode of atrial fibrillation with a ventricular rate of 300-350/mn; investigation (vecto-cardiogram, intra-cavitory ECG) showed the presence of a short circuit of the Kent type, with a high permeability, and localised in the left lateral position; this was confirmed by pericardial cartography. After the surgical division of the accessory pathway, the electrical phenomenon of pre-excitation disappeared. The current possibilities of operating on cases of a Wolff-Parkinson-White syndrome justify carrying out a scrupulous electrophysiological study of each case, so that any accessory pathway can be precisely localised, and its refractory period determined; thus a pathway of preexcitation localised in the left lateral position, and having a short refractory period leading to a high ventricular rate under atrial fibrillation conditions, constitutes an indication for operation which may be urgent.

[Gap phenomenon and supranormal conduction during intermittent left bundle-branch block]. / Phénomène de Gap et conduction supernormale au cours du bloc de branche gauche intermittent

The mechanism of intermittent bundle branch block, whether spontaneous or as a result of vagal stimulation, can be studied by reference to the known facts of atrial stimulation. Three cases with intermittent left bundle branch block were studied by means of an intracavitary electrode, which allowed the potential of the bundle of His to be measured, and was also used for the extrastimulus method of study. In case 1, in which the block was independent of the cardiac rate, a type 1 "Gap" phenomenon (of nodal origin) was demonstrated; the coupling zone in which the extrastimulus overcame the block was situated in two areas, one being late, and the other earlier in a region where the conduction was normal. In case 2, in which the block was dependent upon the heart rate, the "recovery" of the blocked branch after early coupling of the extrastimulus seemed to be associated with the phenomenon of "supra-normal" conduction. In case 3, in which the block was again dependent upon heart rate, the two phenomena of "Gap" and "suppranormality" seemed to act successively when the coupling of the extrastimulus is decreased progressively. These observations allow us to distinguish two types of intermittent left bundle branch block; one, which is not related to heart rate, is characterised by a prolonged refractory period of the left bundle branch, which becomes progressively shorter as the heart rate increases; the other, which is dependent upon tachycardia, is characterised on the one hand by an increased left bundle branch refractory period which does not shorten as the heart rate increases, and on the other by the phenomenon of supranormal conduction.