[Iatrogenic syncopes and malaises]

Syncope or presyncope related to adverse drug reactions are well-known. On the other hand, little is known about the specific role of different drugs. Over one six year period, 1611 patients were referred in our hospital for syncope or presyncope, including 688 in the cardiology department. Among these patients, 420 were 70 years old or more. The search for an adverse drug reaction was systematic, with the help of the French method for causality of adverse drug reaction: knowledge of "extrinsic" criteria (bibliographical data relating to the drug involved); moreover, score on the basis of "intrinsic", chronological and symptomatic criteria. Seventy five patients (11% of the group with syncope leading to admission in cardiology department) were thus retained: score = I2, "possible adverse drug reaction", for 28 patients (37%); score = I3, "probable adverse drug reaction", for 47 patients (63%). Score I4, "definite adverse drug reaction" was not used since it required the readministration of the drug to prove the iatrogenic effect. Average age was 78 years, with a female majority of 69%. Seventy two patients (96%) had previous cardiovascular disease, 37 (50%) previously experienced syncope or presyncope. In addition to the basic assessment, a Holter recording was performed among 56 patients, finding a drug-induced arrhythmia in three cases. In the majority of the patients (59 patients, 79%), the adverse drug reaction consisted of hypotension, clinically obvious in 49 cases. In ten cases, vasovagal syndrome facilitated by the drugs was diagnosed by a tilt-test. The other side effects were eight rhythm disorders and eight severe metabolic disorders. The treatments were always multiple. The involved drug was a cardiovascular therapy in 66% of the cases. The other drug classes were primarily represented by uroselective alpha 1-adrenergic blocking drugs (12%) and psychotropic ones (22%). Among the cardiovascular treatments, ACE inhibitors and diuretics, generally in association, were involved (59%). This study confirms the role for antihypertensive drugs in iatrogenic syncope, its great frequency in elderly patients but also the responsibility of another drug class less often reported, the uroselective alpha 1-adrenergic blocking drugs.

Resumption of right atrial isthmus conduction following atrial flutter radiofrequency ablation

Right atrial isthmus block is currently accepted as a success criterion of atrial flutter ablation. An electrophysiological study performed days after the ablation procedure may show recovery of conduction across the isthmus in some patients, followed by arrhythmia recurrence. However, few data are available on the time course of this recovery and on the monitoring of isthmus conduction at the end of the ablation procedure as a means of increasing the success rate of the procedure. Radiofrequency (RF) catheter ablation was performed in 28 men and 7 women (mean age = 65 +/- 11 years) presenting with common or clockwise atrial flutter (AFL) resistant to 2.9 +/- 1.8 antiarrhythmic drugs. Underlying heart disease was present in 13 patients. The ablation procedure was performed with an 8-mm-tip catheter, by several 45-second applications at a target temperature of 65 degrees C, directed to the isthmus between tricuspid annulus and inferior vena cava. Bidirectional isthmus block (BDB) was created with 4-24 RF applications in all but one patient. Special attention was paid to exclude incomplete block by meticulous mapping during pacing at the coronary sinus os and at the low lateral right atrium every 5 minutes for 20 minutes thereafter. Conduction recovered across the isthmus in 5 patients at 10, 10, 12, 15, and 16 minutes, respectively, and further RF applications were needed to obtain stable block. At a follow-up of 17 +/- 10 months, AFL occurred in the patient without, and in one patient with BDB. Thirty-three of the 34 patients (97%) with persistent BDB remained free of arrhythmia recurrence. This study showed that conduction resumed across the isthmus within 20 minutes, after AFL ablation in 15% of the patients. The long-term results of the procedure can be optimized by ascertaining the persistence of BDB during that period of time.

[Myocardial infarction caused by septic embolism during mitral endocarditis]

Embolic infarction is a rare complication of mitral valve endocarditis. The authors present the case of a patient with a linear vegetation of the anterior mitral leaflet measuring over 15 mm and entering the aortic valve orifice at each systole. This valvular infarction was the cause of an extensive anterior wall infarct treated by primary angioplasty because of haemodynamic instability. The outcome at 3 months was very favourable with regards to the mitral valve. However, a large mycotic coronary aneurysm developed at the site of angioplasty and there were sequellae of a large anterior wall infarction.

[Left intra-atrial membrane without pulmonary vein obstruction: benign condition of progressive evolution? Apropos of 7 cases]

Left triatrial heart is defined as division of the left atrium into two chambers, proximal and distal, by a variably perforated membrane. The data of appearance of symptoms, often in early childhood, is related to the degree of obstruction and the presence or not of an inter-atrial shunt. Widescale usage of echocardiography, the investigation of choice for this diagnosis, has led to the detection of this abnormality in older patients, sometimes asymptomatic, without pulmonary hypertension. Three adults were referred for transthoracic and transoesophageal echocardiography to investigate systemic embolic disease (2 cerebral, 1 mesenteric). Two other adults underwent the same investigations for diagnosis of the aetiology of atrial fibrillation with mitral regurgitation. Two cases were asymptomatic children, one with a clinically benign murmur and the other with ventricular extrasystoles with no malignant features. In these seven cases, transthoracic (n = 5) and/or transoesophageal (n = 7) echocardiography demonstrated a left atrial membrane corresponding to the classical description of cor triatrium. The Doppler study showed no obstruction in 6 cases and minimal obstruction in 1 case. In our series, as in similar cases reported in the literature, the diagnosis of a left atrial membrane did not lead to surgery. Although we do not know the long-term outcome of this abnormality in asymptomatic children, the observations of complications in the adult suggest a potential of evolution which poses the question of optimal management.

[Reproducibility of measurements of blood gas exchange during exercise in mild cardiac failure: need for a preliminary test?]

The reproducibility of blood gas exchange measurements on exercise in chronic cardiac failure has already been established in patients familiar with this technique. The aim of this prospective study was to evaluate the reproducibility of cardiopulmonary parameters on exercise in a population of patients who had never undergone this type of investigation. Twenty patients with chronic cardiac failure in classes I to III of the NYHA classification, with a mean age of 55 +/- 11.5 years and a mean LV ejection fraction of 31.2 +/- 9%, underwent two cardiopulmonary exercise tests (CPX Medgraphic) performed on a bicycle ergometer. Patients underwent maximal exercise stress testing attaining 89% of the theoretical maximal heart rate and 1.14 of the respiratory quotient during the first test. There was no significant change in peak VO2 (22.5 ml/min/kg vs 22.6 ml/min/kg) or in ventilatory anaerobic threshold (12.8 ml/min/kg vs 12.7 ml/min/kg) between the two tests. The ventilatory anaerobic threshold could not be measured in one patient and seemed less reproducible than peak VO2 with a standard deviation of relative differences (T2-T1/T1) of 10.4 versus 7.8%. There was a significant increase in the duration of exercise (7.4 +/- 9.2%; p < 0.002) and a ventilatory flow (4.5 +/-, p = 0.03). This study shows that peak VO2 is a reproducible measurement in mild to moderate chronic cardiac failure, even in the absence of a preliminary test to familiarize the patient with the equipment. The reproducibility of the ventricular anaerobic threshold is less satisfactory than that of peak VO2. The increase in the duration of exercise is more dependent on motivation and should not be taken into account alone in the functional evaluation of chronic cardiac failure.

[Isolated left superior vena cava: value of intraoperative echocardiography for implantation of a cardiac pacemaker]

The authors report the case of a patient presenting with isolated left superior vena cava, for which intracardiac implantation of a cardiac pacemaker was facilitated by intraoperative transthoracic ultrasonographic detection of the course of the ventricular catheter. Transoesophageal ultrasonography confirmed the diagnosis and eliminated a possible associated malformation.