[Evaluation of the cost of complications of automatic implantable defibrillators]. / Evaluation du coût des complications des défibrillateurs cardiaques automatiques implantables.

The automatic implantable defibrillator (AID) has been shown to prevent sudden death but it frequently gives rise to complications. These complications seem to be costly but they do not figure in the economic assessments of AID. From 1989 to 2003, 202 patients (173 men, age 58 +/- 14 years) received consecutively 264 AID in the same centre of implantation. The authors studied the complications of these implantations. The medical indication was secondary (documented spontaneous ventricular tachycardia or fibrillation) in 145 patients (71.8%) and prophylactic in the remaining 57 patients (28.2%). During the 36 month (+/- 35) follow-up, 40.6% patients had an appropriate treatment: 50.3% in the secondary prevention group versus 15.8% in the prophylactic implantation group. The one year, 5 and 15 year survival rates were 99, 88 and 85% respectively. Eighty seven complications were observed resulting in a long term complication in 36.7% of patients. These complications were: inappropriate electric shock, n=24 (27.6%), fractured catheters, n=12 (13.6%), haematomas, n=12 (13.6%), loss of function of the AID, n=10 (11.4%), infection, n=6 (6.8%), pneumothorax, n=7 (8.0%), and others n=16 (18.4%). The cost of these complications was assessed in terms of hospital stay in intensive care (1010.40 euros per day) or in the general cardiology wards (546.70 euros per day). The complications resulted in 502 days of additional hospital stay (5.77 days per complication) with a total cost of 285 655.20 euros (3283.40 euros per complication). The most expensive complications in terms of hospital stay were: infections (24.5 days), fractured catheter (5.75 days), and postoperative haematoma (5.5 days). These results indicate a significant cost of complications which should be indicated in the economic evaluation of AID.

[Risk stratification in atrial and ventricular arrhythmias]. / Stratification du risque dans les troubles du rythme auriculaire et ventriculaire.

Atrial fibrillation, the most frequent arrhythmia, has a growing incidence with increasing age and the most important complication of the disease is thromboembolic events that may be prevented by antivitamin K. They are the most efficient therapeutic class for the prevention of these events but they are associated with an increased haemorrhagic risk leading to a reduced prescription in general practice. Optimisation of the management should be based on an individual evaluation of the thromboembolic and haemorrhagic risks, taking into account age, the presence of an associated heart disease, hypertension, diabetes, history of cerebrovascular event, history of previous haemorrhagic event and the ability to achieve a stable target INR. The challenge in ventricular arrhythmias lies in identifying a high risk of sudden death, mainly related to ventricular fibrillation. In patients with structural heart disease, left ventricular dysfunction is the strongest predictor of sudden death. Non invasive markers such as non sustained ventricular tachycardia, late ventricular potentials, decreased heart rate variability and baroreflex sensitivity, and repolarization altemans are further elements to assess risk. However, most of these markers have a poor positive predictive value and a low specificity. In patients with normal hearts, genetic predisposition may in the future identify high risk patients. The electrophysiologic study with programmed ventricular stimulation remains a costly and invasive method and only has a strong positive predictive value in ischemic cardiomyopathy. More precise algorithms for risk stratification are thus needed that may help the strategy of therapy with prophylactic implantable cardioverter defibrillator in the future.

[Pericardial extravasation as an indicator of congestive heart failure due to thiamine deficiency in a young adult]. / Epanchement péricardique révélateur d'une insuffisance cardiaque à débit élevé par carence en thiamine chez un adult jeune.

INTRODUCTION: Thiamine (B1) deficiency is one of the classical causes of congestive heart failure. Although in the western world and in other developed regions this disorder is generally associated with chronic alcoholism, it may also only occur as a result of a deficient diet. EXEGESIS: A young patient was admitted for electrocardiographic examination, and pericardial extravasation was recorded. The etiological assessment showed a case of congestive heart failure due to thiamine (B1) deficiency. A hemodynamic examination and investigation of thiamine blood levels confirmed this diagnosis. The patient's health status improved following thiamine administration, with complete and rapid regression of symptoms of congestive heart failure. CONCLUSION: Although cardiomyopathic beriberi is infrequent, it should systematically be taken into account in the etiology of congestive heart failure. The present study also notes that a dietary thiamine deficiency is uncommon, but should nevertheless be considered when other symptoms of denutrition are present.

Long-term prognostic value of time domain analysis of signal-averaged electrocardiography in idiopathic dilated cardiomyopathy.

The aim of this study was to evaluate the long-term prognostic value of signal-averaged electrocardiography (SAECG) in idiopathic dilated cardiomyopathy (IDC). Time domain analysis of SAECG was assessed in 131 patients with angiographically confirmed IDC (age 52+/-12 years; 108 men; left ventricular ejection fraction 33+/-12%) using specific criteria in 44 patients with bundle branch block. Late potentials (LP) on SAECG were present in 27% of the patients. Patients with LP had a similar left ventricular ejection fraction and a similar left ventricular end-diastolic diameter than patients with a normal SAECG. With a follow-up of 54+/-41 months, 24 patients suffered cardiac death and 19 had major arrhythmic events (sudden death, resuscitated ventricular fibrillation, or sustained ventricular tachycardia). Patients with LP had an increased risk of all-cause cardiac death (RR 3.3, 95% confidence interval 1.5 to 7.5, p = 0.004) and of arrhythmic events (RR 7.2, 95% confidence interval 2.6 to 19.4, p = 0.0001). Using multivariate analysis, only LP on SAECG (p = 0.001), reduced SD of all normal-to-normal intervals (SDNN) (p = 0.002), increased pulmonary capillary wedge pressure (p = 0.005), and history of sustained ventricular tachyarrhythmia (p = 0.02) predicted cardiac death. A history of previous sustained ventricular tachyarrhythmia (p = 0.0001), reduced SDNN (p = 0.003), and LP on SAECG (p = 0.006) were the only independent predictors of major arrhythmic events. Results were not altered when considering separately patients with or without bundle branch block, or after exclusion of patients with a history of sustained ventricular tachyarrhythmia. This study is one of the first to suggest that LP on SAECG is an independent predictor of all-cause cardiac death and is of high interest for arrhythmia risk stratification in IDC.

Junctional rhythm during slow pathway radiofrequency ablation in patients with atrioventricular nodal reentrant tachycardia: beat-to-beat analysis and its prognostic value in relation to electrophysiologic and anatomic parameters.

INTRODUCTION: Junctional rhythm usually is considered a sensitive but nonspecific marker of successful ablation of the slow pathway in AV nodal reentrant tachycardia. Nevertheless, this junctional rhythm has been little studied, and its relations to recognized predictors of successful radiofrequency (RF) application were never established in any study. METHODS AND RESULTS: Thirty-nine patients underwent RF ablation of the slow pathway for AV nodal reentrant tachycardia. Ninety RF applications were delivered, and each ablation site was determined using three different fluoroscopic projections. Six anatomic zones were defined from low posterior septum to the site of distal His-bundle recording (P1, P2, M1, M2, A1, and A2). Characteristics of junctional rhythm during RF applications were analyzed. Atrial electrogram characteristics at the ablation sites also were studied. All patients had successful slow pathway ablation, without any complication. The ablation sites were located as follows: 41 at P1, 26 at P2, 20 at M1, and 3 in M2. Forty RF applications were successful: 14 of 41 attempts at P1, 7 of 26 at P2, 16 of 20 at M1, and 3 of 3 at M2. Mid-septal ablation site (M1 and M2) was associated with higher occurrence of junctional rhythm (P < 0.0001), earlier first junctional beat (P = 0.008), and earlier occurrence of the longest junctional burst (P = 0.03) compared with posterior ablation site (P1 and P2). The combination of a mid-septal ablation site and a first junctional beat occurring < or = 3 seconds after onset of RF application identified successful RF application with 100% accuracy. Using multivariate analysis, the ablation site, duration of atrial electrogram (including slow pathway potential when present), and occurrence of junctional rhythm were independent predictors of success. CONCLUSION: Successful slow pathway ablation depends on many factors. Junctional rhythm characteristics are related to the site of RF delivery and can be helpful in assessing successful slow pathway ablation.

Comparison of long-term outcome of alcoholic and idiopathic dilated cardiomyopathy.

AIMS: The outcome of alcoholic cardiomyopathy is thought to be better than idiopathic dilated cardiomyopathy if patients abstain from alcohol. The aim of this study was to compare the long-term clinical outcome of alcoholic and idiopathic dilated cardiomyopathy. METHODS AND RESULTS: Of 134 patients with dilated cardiomyopathy and normal coronary angiography, 50 had alcoholic cardiomyopathy; they were compared serially to 84 patients with idiopathic dilated cardiomyopathy. Left ventricular end-diastolic diameter, left ventricular ejection fraction and cardiac index, severity of ventricular arrhythmias, measurement of heart rate variability and results of signal-averaged ECG were similar in both groups. Although alcohol withdrawal was strongly recommended but observed in only 70% of patients with alcoholic cardiomyopathy, both groups had similar outcome in terms of cardiac death after follow-up treatment of 47+/-40 months. Multivariate analysis in the entire cohort demonstrated that increased pulmonary capillary wedge pressure (P=0. 003), alcoholism and lack of abstinence during follow-up (P=0.006) and decreased standard deviation of all normal-to-normal RR intervals (P=0.02) were independent predictors of cardiac death. CONCLUSION: In contrast with previous studies, patients with alcoholic cardiomyopathy did not have a better outcome than patients with idiopathic dilated cardiomyopathy. Alcoholism without abstinence was a strong predictor of cardiac death. This suggests that a more aggressive approach to alcohol cessation is needed in these patients.

[Mid-term complications of automatic implantable cardiac defibrillators]. / Complications à moyen terme du défibrillateur cardiaque automatique implantable.

The incidence and the nature of medium-term complications of automatic implantable cardiac defibrillators (AICD) were studied. Seventy-nine AICD were implanted in 50 consecutive patients (42 men, aged 54.5 +/- 13.7 years). Forty-six patients had spontaneous ventricular arrhythmia. These arrhythmias were resistant to treatment (N = 9), reproducible with treatment (N = 28). In 4 patients, the indication was prophylactic, in 2 a Brugada syndrome, in 2 syncope with reinducible ventricular tachycardia and in 1 patient, torsades with a short coupling interval. Forty-six patients had underlying cardiac disease (ischaemic, N = 28, primary dilated cardiomyopathy, N = 10, others, N = 8). The ejection fraction was > 40% in 32 patients. The average follow-up was 41.3 +/- 34.9 months. Eight patients died, 2 from cardiac failure. Twenty-one patients (42%) had 1 or more complications related to their AICD. These occurred: in the operative period (N = 3): 1 post-shock atrioventricular block, 1 ruptured electrode and 1 increased threshold with amiodarone; in the postoperative period (N = 6): infection in 3 cases, cerebrovascular accident in 1 case, deep venous thrombosis of the left arm in 1 case, pneumothorax in 1 case. In the medium-term, the complications were mainly inappropriate electrical shocks observed in 14 patients related to atrial arrhythmias in 7 cases, sinus tachycardia in 1 case, over-detection of myopotentials in 2 cases and electrode dysfunction in 4 cases. In addition, the authors observed complications related to the material: AICD failure in 1 case, electrode displacement in 1 case, and electrode rupture in 3 cases. The authors conclude that AICD are effective for the treatment of malignant ventricular arrhythmias which justify strict specialist follow-up given the incidence and diversity of their complications.

[Mitral valve prolapse, arrhythmias and sudden death]. / Prolapsus valvulaire mitral, troubles du rythme et mort subite.

Some of the classical concepts of mitral valve prolapse (MVP) should be reviewed in the light of recent publications. It is a condition, according to strict echocardiographic criteria excluding near physiological abnormalities, which affects 2 to 3% of the adult population in the industrialised world. Only repetitive atrial arrhythmias and complex ventricular arrhythmias are more common in this condition than in control groups, the differences being more pronounced in cases of mitral regurgitation. The risk of syncope or sudden death is 0.1% per year, hardly any different to that of the rest of the general adult population (0.2%). However, this risk may attain 0.9 to 2% in cases with mitral regurgitation. The causes of sudden death are unclear (haemodynamic, neurohumoral, arrhythmic, etc...), although there is evidence in favour of malignant ventricular arrhythmias. Detailed clinical, electrophysiological, isotopic and anatomopathological studies have raised doubts as to the direct responsibility of the vascular malformation (or its eventual consequences on the atrial and ventricular chambers) in this mode of fatal outcome. On the other hand, localised or diffuse myocardial disease is often observed, usually a- or pauci-symptomatic, associated with MVP, the responsibility of which is more plausible. Therefore, the physician should adopt a flexible attitude towards these patients, reassuring those with benign symptoms at low risk and following up or actively treating the rarer malignant forms (especially familial, syncopal with mitral regurgitation and/or severe arrhythmias).

Significance of late ventricular potentials in myotonic dystrophy.

In 39 patients with myotonic dystrophy, we found a high percentage of infrahissian cardiac conduction abnormalities (51%) and late potentials (46%), whereas spontaneous and inducible ventricular arrhythmias were rare. These results suggest that the prolongation of QRSD and the duration of the low-amplitude signal on the signal-averaged electrocardiogram were related to delayed activation of the His and Purkinje tissue rather than true late potentials.

Is it possible to identify infrahissian cardiac conduction abnormalities in myotonic dystrophy by non-invasive methods?

OBJECTIVE: To identify intracardiac conduction abnormalities in patients with myotonic dystrophy from their clinical, ECG, and genetic features. METHODS: 39 consecutive patients (mean (SD) age 42. 9 (12.1) years; 16 female, 23 male) underwent clinical examination, genetic studies, resting and 24 hour ambulatory ECG, signal averaged ECG, and electrophysiological studies. RESULTS: 23 patients suffered from cardiac symptoms, 23 had one or more cardiac conduction abnormality on resting ECG, one had sinus deficiency, and 21 (53.8%) had prolonged HV intervals. No correlation was found between the severity of the neurological symptoms, onset of disease, cardiac conduction abnormalities on ECG, and the intracardiac conduction abnormalities on electrophysiological study. The size of the DNA mutation was longer in the abnormal HV interval group than in the normal HV interval group (3.5 (1.8) v 2.2 (1.0) kb, p < 0.02). Signal averaged ECG parameters (total QRS duration (QRSD) and duration of low amplitude signals /= 100 ms with LAS 40 >/= 36 ms identified patients with an abnormal HV interval with good sensitivity (80%) and specificity (83. 3%). CONCLUSIONS: Infrahissian conduction abnormalities are common in myotonic dystrophy and can be identified using signal averaged electrocardiography.

[Diagnosis of coronary disease: thallium-201 dipyridamole tomoscintigraphy of the myocardium]. / Détection de la maladie coronarienne: performances diagnostiques de la tomoscintigraphie myocardique au thallium-201 après dipyridamole.

OBJECTIVES: Determine the diagnostic performance of thallium-201 myocardial scintigraphy using dipyridamole injection for the detection of coronary heart disease (myocardial ischemia and/or necrosis). Determine for each coronary artery the degree of angiographic stenosis for optimal diagnostic performance. PATIENTS AND METHODS: The study included 309 patients who underwent coronarography within 6 months of the scintigraphy examination. None of the patients experienced a coronary event during this interval. Diagnostic performance of the scintigraphic exploration was compared with angiographic findings (stenosis 70%) used as the gold standard. The degree of angiographic stenosis for optimal scintigraphic performance was determined from the receiver operating characteristic (ROC) curves. RESULTS: The sensitivity of scintigraphy to detect angiographically demonstrated coronary disease was 84% with a specificity of 72%. The positive and negative predictive values were 87% and 66% respectively. Test accuracy was 80%. Sensitivity was better for detecting lesions of the anterior interventricular coronary than for the right coronary or circumflex. In addition, sensitivity varied with the number of vessels involved: 76% for single-vessel disease versus 90% for two- or three-vessel disease. The data analysis also suggested that an angiographic stenosis threshold of 50% provided optimal predictive value for scintigraphy for each of the three vessel territories. An analysis based on maximal stenosis in each patient, notwithstanding the congruency between lesion localization and diseased vessel territories, was found to provide less diagnostic precision. CONCLUSION: Thallium-201 dipyridamole myocardial scintigraphy offers diagnostic performance comparable to that established with thallium-201 scintigraphy performed after exercise alone. Scintigraphic detection of a perfusion defect generally corresponds to an angiographic stenosis of 50%.

Effect of verapamil on QT interval dynamicity.

Using measurements of QT/RR slopes with a computerized Holter system, QT interval dynamicity was evaluated in 19 patients with normal structural heart before and 2 months after oral treatment with verapamil prescribed for paroxysmal atrioventricular nodal reentrant tachycardia. Verapamil significantly shortened QT at low heart rates, mainly in the diurnal period, and this characteristic may explain, in part, the previously reported protective effect of verapamil against torsades de pointes.

Influence of duration and hour of recording on spectral measurements of heart rate variability.

UNLABELLED: Frequency-domain analysis of heart rate variability provides information about influences of autonomic nervous system on the heart and can be measured on short-term or long-term electrocardiogram recording. We compared heart rate variability on 24 h electrocardiogram recording with measurements of heart rate variability over shorter periods of 1 h and 12 h in order to determine the influence of duration and hour of recording on the heart rate variability parameters in the frequency domain. Heart rate variability was analyzed in 24 subjects with normal heart, with measurement of total power (Tot P), ULF, VLF, LF, HF and LF/HF ratio. Reference measurements over 24 h were compared with measurements over 4 periods of 1 h (2 AM-3 AM, 8 AM-9 AM, 2 PM-3 PM, 8 PM-9 PM) and over 4 periods of 12 h (2 AM-2 PM, 8 AM-8 PM, 2 PM-2 AM, 8 PM-8 AM). The correlations with measurements over 24 h were lower for the measurements over 1 h than for the measurements over 12 h. ULF had the lowest mean of correlation coefficients for measurements over 1 h and 12 h, whereas the other frequency bands had high correlations with measurements over 24 h. When using Bland and Altman method, only measurements over 2 AM-2 PM and 2 PM-2 AM periods were a reliable estimation of heart rate variability over 24 h. CONCLUSION: Spectral measurements of heart rate variability over 12 h have high correlations with measurements on 24 h. ULF is the parameter the most affected by the duration of the recording. Spectral measurements over 2 AM-2 PM and 2 PM-2 AM periods are reliable appreciations of heart rate variability over 24 h.

Effect of flecainide on heart rate variability in subjects without coronary artery disease or congestive heart failure.

Heart rate variability is a noninvasive indicator of autonomic nervous system activity. The role of the autonomic nervous system in the genesis of atrial or ventricular arrhythmias is now well established. Little is known about the effects of flecainide on heart rate variability in patients with normal heart structure, the main population receiving flecainide. This study was designed to evaluate the effects of flecainide on heart rate variability in patients without coronary artery disease or congestive heart failure. Time and frequency domain analysis of heart rate variability on 24-hour electrocardiogram recording were assessed in 40 patients with normal echocardiography and without evidence of coronary artery disease before and after 2 months of oral treatment with flecainide (321 +/- 57 mg/day) prescribed for Wolff Parkinson White syndrome with circus movement tachycardia. Flecainide significantly decreased all parameters of heart rate variability in the time domain (median delta% -10% to -25%) and in the frequency domain (median delta% -27% to -38%), including the markers of vagal activity. There was no correlation between plasma concentrations of flecainide and reduction in heart rate variability. It was concluded that in subjects without coronary artery disease or congestive heart failure, flecainide decreases all the measurements of heart rate variability and this decrease is not related to plasma concentrations of flecainide.

[Loss of a stent in the left main coronary artery and secondary migration into the left circumflex artery needing surgical extraction. Apropos of a case]. / Perte dans le tronc commun de la coronaire gauche d'une endoprothèse et migration secondaire dans l'artère circonflexe ayant conduit à une extraction chirurgicale. A propos d'un cas.

The authors report a case of accidental loss of a coronary stent in the coronary arteries and its migration into the circumflex artery. This complication occurred during revascularisation of the left anterior descending artery. In view of a dissection at the site of angioplasty and the migration of the stent, emergency surgery was undertaken comprising bypass grafting of the left anterior descending and arteriology of the left circumflex arteries to recover the stent. This is a rare complication, the frequency is probably underestimated. The authors discuss the factors predisposing to failure of implantation and the means of recovering the stents. The consequences of loss of a stent in the coronary or systemic circulations are also commented.

[Is isolated atrial fibrillation genetically determined? Apropos of a familial history]. / La fibrillation auriculaire isolée est-elle une maladie génétique? A propos d'une histoire familiale.

The authors report five cases of apparently lone atrial fibrillation in five members of the same family from three generations. The atrial fibrillation occurred at an early age and rapidly became permanent in all cases. With time, in the absence of complications, structural cardiac abnormalities were documented by echocardiography (biatrial dilatation and mitral and tricuspid regurgitation). These observations raise the question of genetic predisposition to lone atrial fibrillation at least in this particular clinical context.