Introduction of permanent cardiac stimulation/defibrillation leads via the retro-pectoral veins.

When the cephalic vein route is not easily accessible for the introduction of permanent stimulation/defibrillation leads, retro-pectoral veins can be looked for, which are usually present and suitable in most patients. As with the cephalic vein route, it is a safer approach than direct subclavian vein puncture. Moreover, using a guidewire and a split introducer increases the rate of successful cannulation.

[Traumatic aortic regurgitation: diagnostic, management and treatment]. / Rupture traumatique de la valve aortique. Diagnostic, prise en charge et traitement.

Traumatic aortic valve regurgitation is a rare complication of non-penetrating thoracic trauma. The most frequent lesion is the isolated injury of the non-coronary cusp. Actually, the transoesophageal echocardiography is the procedure of choice to confirm the diagnosis and to reveal the associated cardiovascular lesions. Surgical management with early operation is the best policy, however this surgery can be delayed for treatment of other life-threatening injuries. Up today, aortic valve replacement (AVR) was recommended to repair traumatic aortic valve regurgitation; nevertheless, in the recent international literature, the number of cases reports with conservative surgery (CS) is increasing: 10 AVR (group I) and 10 CS (group II). Analysis of the post-operative and long term periods shows good results: it confirms the excellent clinical evolution in the group I (mean time of follow-up: 18.2 +/- 16.3 months), and reveals satisfactory results in the group II for patients with isolated lesion (mean time of follow-up: 29.1 +/- 30.7 months). In conclusion, each time the traumatic aortic regurgitation is due to an isolated lesion, the conservative surgery should be performed in order to avoid aortic valve replacement and its potential complications especially in young patients with healthy valves. However, the aortic valve replacement is the safest technique for complex or multiple injuries of the aortic valve.

[Atrial lead placement in the right atrial appendage during recent or chronic arrhythmia]. / Implantation de la sonde atriale dans l'auricule droit chez des patients en arythmie atriale récente ou chronique en vue d'une régularisation différée du rythme. Performance de la sonde à 6 mois.

An atrial arrhythmia could be encountered during the atrial lead implantation. The lead placement must subsequently be delayed after restitution of the sinus rhythm or completely abandoned. The authors investigate the atrial lead placement during atrial arrhythmia and the lead performance at 6-month follow-up. The study population was 65 patients aged 78.5 years, 42 males and 28 structural heart diseases. They were implanted for sick sinus syndrome (n=14), atrioventricular block (n=44), infra-hisian conduction abnormality (n=7) in association with an atrial fibrillation (63.1%), an atrial flutter (24.6%) or an atrial tachycardia (12.3%). The onset of the arrhythmia was < or = 7 days (47.7%) or > 7 days (52.3%). An atrial lead was placed in the right atrial appendage under fluoroscopic control. If the sinus rhythm was not restored at 1 month, an electrical cardioversion was performed. The per-implantation atrial signal amplitude was 2.2+/-1.5 mV (range 0.5 mV to 7 mV). Sinus rhythm was restored in 54 patients. At 1 month, one patient was in an incessant atrial fibrillation. The 53 patients in sinus rhythm had a good atrial lead performance. Out of 46 patients who completed the 6-month follow-up, 4 had an arrhythmia recurrence. The 42 patients in sinus rhythm had a good atrial lead performance. At 1 and 6-month follow-up, the atrial pacing threshold (1.1+/-0.7 V vs 1.2+/-1.0 V, ns) and the atrial signal amplitude (2.1+/-1.0 mV and 2.1+/-0.9 mV, ns) were stable. Comparing the patients with a recent or a chronic arrhythmia, the pacing thresholds (1.2+/-1.1 V vs 1.14+/-0.8 V, ns), the atrial signal amplitudes (2.17+/-0.9 mV vs 2.05+/-0.9 mV, ns) and the proportion of satisfactory pacemaker performance in DDD(R) mode for the patients in sinus rhythm (100% vs 100%, ns) did not statistically differ between the two groups at 6 months. In conclusion, the placement of an atrial lead in the right atrial appendage during an atrial arrhythmia is feasible with a good lead performance at 6 months in sinus rhythm regardless the onset time of the arrhythmia and provides a satisfactory atrial-based pacing with the preservation of the atrioventricular synchrony.

Pseudofracture of an ICD lead.

A proximal pseudofracture of a Medtronic 6936 defibrillating lead adjacent to the ICD pulse generator was found on X ray. At this site, the multifilar metallic connector joins the stimulating lead before coiling around it. Conventional X ray of the abdomen does not visualize this connection. During ICD replacement, lead impedance should be routinely measured.

[Transformation of left bundle branch block into simulated bundle branch block after ablation of the right bundle in a patient with branch-to-branch reentry ventricular tachycardia]. / Transformation d'un bloc de branche gauche en bloc de branche déguisé après ablation de la branche droite chez un patient présentant des tachycardies ventriculaires par réentrée de branche à branche.

Masquerading bundle branch block associates left bundle branch block in the standard lead and right bundle branch block in the precordial leads. Mr R., 67 year old, was referred for investigation of syncope. He had a history of idiopathic dilated cardiomyopathy (normal coronary arteries; EF: 14%, CI: 2.2 l/min/m2 at later investigations). The ECG showed LBBB with left axis deviation, a PR interval at the upper limits of normal and ventricular premature beats. During observation, he had another syncopal episode and the ECG showed wide complex tachycardia (160 bpm) reduced by external cardioversion. Electrophysiological investigations showed inducible VT due to bundle branch reentry. The HV interval in sinus rhythm was 80 ms. Radiofrequency ablation of the right bundle led to first degree AVB with masquerading bundle branch block with an increased HV interval of 120 ms. The usual facility of ablation of the right bundle branch block is an argument in favour of the hypothesis whereby masquerading bundle branch block is a variety of RBBB with severe conduction defects of the two branches.

[Therapeutic possibilities for the management of vasovagal syncopes]. / Possibilités thérapeutiques pour la prise en charge des syncopes vasovagales.

Since the advent of the tilt test, our understanding of the pathogenesis of vasovagal syncope has progressed greatly. Two mechanisms lead to the sudden fall in blood pressure: on one hand a series of interrelated neuroreflexes, and on the other, neuroendocrine effects. Although our understanding is not complete, new therapeutic measures can be proposed beyond simple empiric prescriptions of vagolytic agents. The efficacy of different treatments is yet to be proven due to the need for long controlled trials with large numbers of subjects. In the early studies versus placebo, no significant evidence of a preventive effect against recurrent malaise could be distinguished from the placebo effect. Complementary investigations such as the tilt test also act as a placebo. While firm recommendations for effective prevention cannot be established until the results of controlled trials are available, it is nevertheless possible to propose a reasonable approach to management.

[Comparative data of tilt test with or without isoproterenol in investigation of unexplained unconsciousness and syncope]. / Données comparatives du test d'inclinaison avec ou sans isoprotérénol dans l'exploration des syncopes et lipothymies inexpliquées.

The tilt test is a widely used diagnostic tool for the investigation of syncope of suspected vasovagal origin. Some workers suggest that the sensitivity should be increased at the price of the loss of some specificity. Passive (non-sensitised) or isoproterenol (sensitised) protocols have not been widely studied on a large scale. The authors report the respective results of two protocols (passive and sensitised with isoproterenol proposed by Benditt et al.) applied to the same subject at 24 hours' interval in a random order in a series of 108 patients (age 56 +/- 19.3 years, 72 men) with unexplained syncope or malaise. After 30 minutes in decubitus, an 80 degrees tilt was maintained for 45 minutes for the passive test and for 25 minutes for the sensitised test, followed by a continuous infusion of isoproterenol in 10 minutes intervals of decubitus and inclination at successive doses of 1.3 and 5 micrograms/min. One or both tests were positive in 62 patients (57.4%). The overall concordance of the two tests (both positive or both negative) was 53.7%. In a subgroup of 60 subjects with clinically suggestive vasovagal attacks, the sensitivity of the passive test was 25% compared with 73.3% with the isoproterenol test (p < 0.001). Based on this difference of sensitivity between the two protocols, and knowing the good specificity of the isoproterenol test, the authors recommended the isoproterenol test as being of great practical value.

Effect of pacing rate on regional left ventricular wall motion. Assessment by quantitative analysis of equilibrium radionuclide angiography.

We evaluated the hemodynamic impact of right ventricular pacing at different stimulation frequencies. Fourteen patients with a right ventricular pacemaker (VVI pacing with retrograde P wave) but without clinical and electrocardiographic evidence of coronary artery disease underwent two equilibrium radionuclide angiographies: one under low heart rate (50/60 beats per minute) and the other under fast heart rate (90/100 beats per minute). Left ventricular global and sectorial ejection fractions, amplitude and phase images of first harmonic, and sectorial phases of left ventricle were analyzed. In twelve patients (84.7%), sectorial ejection fraction abnormalities in the left ventricular apicoseptal and inferoapical regions were observed under low heart rate, and worsened under fast heart rate, while new onset sectorial ejection fraction abnormalities under fast heart rate were observed in the other two patients with normal sectorial ejection fraction under low heart rate. Sectorial ejection fractions of left ventricular apicoseptal and inferoapical regions significantly changed between low and high heart rate (- 14.1 +/- 3.8%, p < 0.005; - 7.5 +/- 2.4%, p < 0.01 respectively). Left ventricular sectorial phases were abnormal in only two patients (14.3%) under low heart rate, and in twelve patients (84.7%) under fast heart rate. Our study confirms that left ventricular regional wall motion abnormalities during VVI pacing significantly worsen under fast heart rate in comparison to those under low heart rate.

[Refractory sinus tachycardia: late complication of radiotherapy]. / Tachycardie sinusale rebelle: complication tardive de la radiothérapie.

The authors describe a case of sinus tachycardia, an unusual cardiac complication of mediastinal radiotherapy; occurring in two patients by the first days of treatment and persisting for several years. No other cause for this tachycardia could be detected in either case. Electrophysiological investigation of one of the two patients was normal. Despite the risk of a high-degree conduction disorder, "symptomatic" beta-blocker treatment was prescribed, but only induced a limited effect.

Relationship between interatrial conduction times and left atrial dimension in patients undergoing atrioventricular stimulation.

Interatrial conduction time (IACT) and left atrial dimension (LAD) were determined in 75 patients (41 males, 34 females, mean age 78.2 +/- 7.9 years) undergoing atrioventricular (AV) stimulation. The LAD was measured by M mode echocardiography as the distance between the posterior aortic wall and the posterior left atrial wall. The IACT was determined during a transvenous dual chamber pacemaker implant done under local anesthesia (lidocaine). The spontaneous interatrial conduction time (SIACT) was measured from the intrinsic deflection (ID) of the right atrium recorded in a unipolar mode (unipolar J-shaped lead positioned in the right appendage) to the ID of the left atrium (bipolar esophageal lead, left atrial positive deflection equal to the negative one) during sinus rhythm. The right atrium then was paced at a rate slightly greater than the spontaneous one. The paced interatrial conduction time (PIACT) was measured from the stimulus artifact to the left atrial ID. The PIACT was also measured during incremental right atrial pacing (10 beats/min step increase to 180 beats/min) and, from these measurements, the maximum increase of PIACT (MIPIACT) was deduced. The LAD was measured at 39.5 +/- 8.7 mm, SIACT at 70.3 +/- 24.8 msec, PIACT at 118.8 +/- 27.9 msec, and MIPIACT at 16.5 +/- 16.4 msec. We found highly significant relationships between SIACT and LAD (P = 0.0006, r = 0.39), PIACT and LAD (P = 0.0001, r = 0.45), and MIPIACT and LAD (P = 0.0006, r = 0.38). We also noted that the LAD was greater in patients in whom MIPIACT was > 10 msec than in patients in whom the MIPIACT was negligible (P < 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)

[Severe arrhythmia in the elderly: a prospective hospital study]. / Troubles du rythme graves du sujet âgé; étude prospective hospitalière.

The prevalence of arrhythmia increases with age. Considered as an "ordinary" event in elderly patients, these arrhythmias may nevertheless have serious consequences. This study was undertaken to determine the clinical, aetiological and prognostic features of serious arrhythmias in a population of elderly subjects (> or = 70 years) hospitalised over a 20 months period and comprising 202 patients (103 women, 99 men, mean age 79.6 +/- 5.9 years). Supraventricular arrhythmias are the most common by far (84.2%): 51.4% of patients had atrial fibrillation, 15.3% had atrial flutter; 12.9% had focal atrial tachycardia, 4.5% had junctional tachycardia. Of the ventricular arrhythmias (15.8%), there were 12 sustained ventricular tachycardias, 4 torsades de pointes and 1 ventricular fibrillation. The increased duration of hospital stay (10 +/- 6 days on average) is related not to age but to the type of arrhythmia (longer for ventricular arrhythmias) and to left ventricular dysfunction. The main complications of arrhythmias were cardiac failure (52.4%), neurological deficits (37.4%) and angina (18.6%). Electrocardiographic signs of atrioventricular block were present in 62% of cases and QRS changes in 47.3% of cases. Ventricular arrhythmias were more commonly associated with intraventricular conduction defects, signs of myocardial necrosis and prolongation of the QT interval; they were also common in patients with left ventricular dysfunction and when the left ventricle was dilated. The aetiology of ventricular arrhythmias was mainly iatrogenic (50%) and ischaemic (21.8%), whereas the aetiologies of the supraventricular arrhythmias were varied, 14.7% of cases being idiopathic. Conversion to stable sinus rhythm was obtained in half the patients. A pacemaker was implanted in 10.8% of cases. The hospital mortality was 4.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Interatrial conduction in patients undergoing AV stimulation: effects of increasing right atrial stimulation rate.

To evaluate the frequency of spontaneous or rate dependent interatrial blocks, the interatrial conduction time (IACT) was studied on 100 consecutive patients (mean age 78.3 +/- 7.8 years) during a transvenous dual chamber pacemaker implant. The spontaneous interatrial conduction time (SIACT) was measured from the intrinsic deflection (ID) of the unipolar right atrial signal to the ID of the left atrial signal recorded in a bipolar way by an esophageal lead. The paced interatrial conduction time (PIACT) was measured from the stimulus artifact to the left atrial ID, when the atrium was paced at a slightly higher rate than the spontaneous rate and during incremental atrial pacing. From these measurements, the maximum increase of PIACT (MIPIACT) was deduced. In this elderly population, the PIACT was similar (117 +/- 26.9 msec) to the data in the literature. However, there were large interindividual variations that were also found in SIACT. We found a close correlation between SIACT and PIACT (P < 0.0001). PIACT was on average 50 msec longer than SIACT. SIACT increased with age (P < 0.03). The MIPIACT was 15.3 +/- 15.2 msec. In the majority of patients, the MIPIACT was > 10 msec, and even reached 90 msec in one patient. MIPIACT was longer in patients with a PIACT exceeding 110 msec (P < 0.004). Based on IACT alone, the AV interval must be lengthened on average by 50 msec when changing from atrial tracking-ventricular pacing to atrial pacing-ventricular pacing, but large individual differences must be kept in mind. Elderly people should probably have a longer AV delay.

[How to evaluate the cost/effectiveness ratio of different therapies of coronary disease]. / Comment évaluer le rapport coût/efficacité des différentes thérapeutiques de la maladie coronarienne.

The results of epidemiologic studies on the efficacy of different strategies of prevention or improvement of the prognosis of coronary artery disease are generally expressed in terms of percentage reduction of risk; for example, the treatment of hypercholesterolaemia reduces the risk of coronary death by 21%. In order to improve the assessment of the efficacy of these approaches the authors propose to take into account the number of subjects which needs to be treated each year to prevent one cardiovascular event more than the control group (for example, in hypercholesterolaemia, 1,736 patients). This number depends on the reduction of risk and also on the incidence of complications in the control group. Using this method, the authors classified different therapeutic strategies in order of their efficacy: thrombolytic therapy in the acute phase of myocardial infarction, then aortocoronary bypass grafting of left main coronary or triple vessel disease, secondary prevention with stopping smoking, and betablocker therapy. Finally, primary prevention with anti-smoking campaigns, treatment of hypertension and hypercholesterolemia. Based on this figure and knowing the annual cost of patient treatment, it is possible to calculate a cost-effectiveness ratio for each of these therapeutic interventions.

Correlations of left ventricular diastolic parameters and heart rate: assessment through right ventricular pacing.

This study evaluated the correlations between left ventricular (LV) diastolic parameters assessed by equilibrium radionuclide angiography (ERNA) and heart rate (HR) through right ventricular pacing. Twelve patients with a permanent right ventricular apex pace-maker were included. Serial ERNA studies were performed under 6 sets of pacing cycle length (heart rate = 52, 62, 72, 82, 92, 104 beats/min) for each patient. The left ventricular ejection fraction was 49.9% +/- 3.1% under pacing HR of 52 bpm and 43.8% +/- 3.1% under pacing HR of 104 bpm. The peak filling rate (PFR) increased very significantly with HR (r = 0.98, P less than 0.001). When the relative changes of end-diastolic volume were taken into account, the correlation between PFR and HR remained significant (r = 0.94, P less than 0.001). The absolute time to PFR (TPFR) did not significantly change with HR, but the ratio of TPFR to cycle length strongly correlated with HR. Our study clearly demonstrates that the PFR assessed by ERNA increases and the TPFR occupies an increasing proportion of the cycle length as HR increases. Therefore, LV diastolic parameters should be normalized for HR in clinical applications. In particular, HR changes should be considered when LV diastolic parameters are used for the assessment of therapeutic interventions.

[Ischemic clinical forms of hypertrophic cardiomyopathies: differential diagnosis with myocardial infarction. Apropos of 15 cases]. / Formes cliniques ischémiques des cardiomyopathies hypertrophiques: diagnostic différentiel de l'infarctus du myocarde. A propos de 15 cas.

This study reports 15 cases of ischaemic clinical forms of hypertrophic cardiomyopathy (HCM). In this retrospective study over a 3 year period, 15 patients with HCM presented with clinical and electrocardiographic signs simulating unstable angina (N = 5) or myocardial infarction (N = 10). All patients had chest pain lasting at least 20 minutes with pseudo-ischaemic ECG changes. Two patients were given thrombolytic therapy. The clinical and enzymatic outcome and results of complementary investigations (including coronary angiography) confirmed the absence of coronary artery disease. The diagnostic of HCM was made by echocardiography. These cases were all apparently primary forms of HCM without intraventricular pressure gradient under basal conditions. Three of the patients were known cases of HCM but the condition was diagnosed after the ischaemic presentation in the other cases. Eight of them had however been considered to have had coronary insufficiency for an average of 5 years. The clinical presentation of HCM represents a difficult differential diagnostic problem with myocardial infarction. Echocardiography is of little help in distinguishing the 2 diseases as septal hypokinesis is often observed in HCM. The clinical course usually reestablishes the diagnosis within a few hours but the delay is often too long in this situation of therapeutic emergency and the indications of thrombolysis may be wrongly posed. Although there is no available formal means of distinguishing the two conditions, this study underlines that this clinical form of HCM is not rare and that the diagnosis should be keep in mind with the other differential diagnoses of myocardial infarction.

Effects of short-term administration of dobutamine on left ventricular performance, exercise capacity, norepinephrine levels, and lymphocyte adrenergic receptor density in congestive heart failure.

This study was designed to determine the feasibility of identifying those patients with chronic heart failure who will be improved by dobutamine infusion. Twenty-two patients with stable heart failure were treated by infusion of an average dobutamine dose of 12.5 ng/kg/min for 36 hours, then again during a 4-hour session once a week for 1 month. Patients were evaluated by clinical, ergometric, and biochemical parameters (plasma norepinephrine and lymphocyte beta-receptor density) before and after every infusion. Hemodynamics were assessed before and during the first dobutamine infusion. A test with isoproterenol was performed prior to the start of dobutamine therapy. All patients exhibited hemodynamic improvement, which peaked at the 12th hour (55% increase in the cardiac index [p less than 0.01]; 35% reduction in the filling pressure and systemic arterial resistance). Five patients stopped the study prematurely. Nine patients (group 1) were clinically improved according to their NYHA classification. Eight patients (group 2) remained stable or had progressive disease. The lymphocyte beta-receptor density before dobutamine infusion was significantly higher in group 1 than in group 2 (66 +/- 12 vs. 46.7 +/- 18 fM/mg; p less than 0.01). Finally, a good correlation (p less than 0.05) was observed between the beta-receptor level and the isoproterenol dose required to obtain a heart rate of 130 beats/min.