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The aim of this study was to analyze the onset mechanisms of atrial tachyarrhythmias using a dedicated diagnostic system in 83 recipients of DDDR pacemakers implanted for standard clinical indications. The pulse generator was programmed in DDD mode, at 60 beats/min, and the diagnostic instrument was programmed to document atrial tachyarrhythmic episodes at rates >200 beats/min. Onset mechanism was defined as the combination of ambient rhythm and trigger. Various underlying rates and rhythms patterns, including tachycardia, increasing frequency of premature atrial complex (PAC), underlying heart rate increase, restart, and no specific underlying rhythm, and various triggers, including single, multiple, or short runs of PACs, sudden rate decrease, and sudden onset of atrial tachyarrhythmia were included in the combined classification. Atrial tachyarrhythmic episodes were documented on one follow-up interrogation in 48 of the 83 patients. The pacing indications consisted of high degree atrioventricular block in 19 patients, bradycardia-tachycardia syndrome in 22, and isolated sinus node dysfunction in 6 patients. The onset mechanisms of 318 episodes were recorded and analyzed. A variety of triggers were observed in 33 of the 48 patients, and 39 patients had various ambient rhythms. Among 20 documented onset mechanisms, the most common were increasing frequency of PAC + short runs (17%), no specific ambient rhythm + sudden onset (24%), and increasing frequency of PAC + sudden onset (12%). There were wide intra- and interpatient variations in onset mechanisms, suggesting that state-of-the-art pacemakers should represent versatile diagnostic tools and offer flexible pacing methods to refine the management of atrial tachyarrhythmias. [ABSTRACT FROM AUTHOR]

Introduction: Because of its excellent negative predictive value for diagnosing coronary stenoses, multislice computed tomography (MSCT) may be a way to assess the absence of significant coronary stenosis. We discussed its place in aeromedical decision-making for aircrew members with a low level of cardiovascular risk factors and acquired left bundle branch block (LBBB)., Methods and Results: During the period 2002-2004, 12 male aircrew members (mean age: 42.9 yr) with acquired LBBB were admitted to our cardiovascular and aeronautical department. The exploration of LBBB was classical, including an electrophysiological study, the usual coronary angiography, and MSCT. All the morphological explorations of the coronary tree were normal., Discussion: In addition to complex electrophysiological mechanisms, coronary artery disease (CAD) is suspected, but remains infrequent in some EKG findings such as acquired LBBB, especially for patients with low cardiovascular risk factors as demonstrated with our aircrew members. However, in aerospace medicine the expert needs to prove the absence of CAD. The use of standard examinations (exercise stress test, stress myocardial scintigraphy, etc.) is controversial because of artifacts and a conventional coronary angiography is necessary. According to previous studies, including using a validated technique in our department (with 16-slice computed tomography), the excellent negative predictive value of MSCT (97 to 99%) may be a way to avoid invasive exploration during the investigation of a newly acquired LBBB in aviators with low cardiovascular risk.

The electrocardiographic appearances and the significance of right bundle branch block were described at the beginning of the 20th century. Typical appearances include prolongation > 0.12 s of the QRS complex, RR' or rR' or Rr' appearances in V1 and widened S waves in the leads exploring the left ventricle (SI, aVL, V5 and V6). A delay in the appearance of the intrinsic deflection > 0.08 s may also be observed in the right precordial leads and negative T waves with ST depression may be seen in V1 and sometimes in V2. Left axis deviation of the QRS complex greater than - 45 degrees suggests associated left anterior hemiblock. Right axis deviation beyond + 120 degrees is equivocal. The principal differential ECG diagnosis is the Brugada syndrome, a familial arrhythmogenic autosomal dominant cardiomyopathy of variable penetration. This diagnosis is suggested when ECG abnormalities are observed in patients with a personal or family history of sudden death. Right bundle branch block only seems to have haemodynamic consequences in cardiac failure with associated asynchrony of the left ventricle or in certain cases of right ventricular dilatation encountered in congenital heart disease. The prognosis of right bundle branch block in the absence of underlying cardiac disease is good but it may be poor in other cases, particularly coronary artery disease. Moreover, the prognosis of right bundle branch block to complete atrioventricular block is rare in the absence of associated cardiac disease.

Introduction: The association of vasoplegic shock and myocardial infarction in a patient under iloprost treatment for critical ischemia of the lower limbs has not previously been reported., Observation: A 56 year-old man suffering from type 2 diabetes, hypertension and dyslipidemia developed critical ischemia of the right leg and was treated with iloprost. On the 19th day of infusion, he developed a vasoplegic shock with myocardial infarction. The shock resolved and he recovered from the infarction., Discussion: This case report indicates the need for reinforced blood pressure and electrocardiographic monitoring in diabetes patients treated with iloprost.

The consequences of implanting an automatic cardioverter defibrillator (ICD) on vehicle driving in France are poorly known. This retrospective study examined the behaviour at the wheel of ICD recipients who were recommended to abstain from driving for 3 to 6 months after device implantation. The study population included 98 patients (mean age = 59.5 +/- 14.8 years) followed for a mean of 24. +/- 23.9 months, who underwent ICD implant for ventricular tachycardia (65% of patients ventricular fibrillation (15%), syncope (8%), as part of a research protocol of myocardial cell transplantation 6%, or for primary prevention (5%). The underlying heart disease was ischemic in 59% of patients dilated cardiomyopathy in 11%,hypertrophic cardiomyopathy in 8%, valvular in 6%. Brugada syndrome in 4%, right ventricular arrhythmogenic cardiomyopathy in 2%, and miscellaneous disorders in 9% of patients. Five patients died without post mortem interrogation of the ICD. Only 28% of drivers remembered, and 13% observed, the recommended driving limitations. However, 45% (the oldest) claimed to drive prudently. During follow-up, 47% of patients received an ICD shock. Their mean it ventricular ejection fraction was 34 +/- 14%, versus 43 +/- 18% in patients who received no ICD therapy (p = 0.015). Syncope occurred in 16% who received ICD shocks. Shocks were delivered during driving in 6 patients, without consequent accident. Despite their non-observance of recommended driving limitations. ICD recipients suffered few traffic accidents. Legislation in France should reproduce the guidelines issued by European professional societies and enacted by the British laws.

Aerobatics is an aerial sport which has many physiological constraints, principally cardiovascular, with a risk if not adapted of sudden mid-air incapacity which could jeopardise aviation safety, and thus justifies the selection and surveillance of pilots. The aeronautical constraints during flight are multiple, related to the environment traversed, how the aircraft functions and its movements. Those which cause accelerations (+G in particular) pose the problem of haemodynamic tolerance because they can induce loss of consciousness due to cerebral hypoxia. Tolerance of acceleration varies among individuals; it can be improved with training, certain protective manoeuvres, and is reduced by hypoxia, certain medications, dehydration and heat. Moreover, in aerobatics certain tricks require manoeuvres which reduce this tolerance to +G accelerations. This is the "push-pull" effect (_G acceleration immediately followed by +G acceleration). This leads to a risk of sudden loss of consciousness with a load factor much lower than that which the pilot knows he is capable of tolerating. Besides the haemodynamic effects, the existence of an actual acceleration cardiomyopathy has been suggested but has not been proven in man. Finally, while changes in cardiac rhythm during accelerations are usual and relate to changes in vaso-sympathetic balance, ventricular and supra-ventricular rhythm disturbances are rare and are related to the intensity and duration of the acceleration.

The authors report 3 cases of resuscitated sudden death in which the investigations clearly showed coronary spasm. This was demonstrated by systematic coronary angiography with an ergometric test. Two patients underwent electrophysiological investigations which were normal. The three patients were prescribed long-term calcium antagonist therapy and one of them underwent coronary angioplasty. With a follow-up of 6 months to 3 years, there was no clinical recurrence or documented arrhythmia. A review of the literature shows that this is a cause of sudden death which is probably underestimated and unrecognised. Electrophysiological investigations often give disappointing results and medical therapy is the keystone of treatment. Coronary angioplasty and implantation of an automatic defibrillator are second-line treatments reserved to forms refractory to medical therapy.

The potential severity of amiodarone-induced hyperthyroidism, particularly in severe cardiopathy cases, necessitates a regular clinic and biologic thyroid control. The break in amiodarone and a medical treatment (synthetic antithyroid drugs, steroids, perchlorate of potassium) can be ineffective. The authors report the case of a patient with an right ventricle arythmogenic dysplasia, without thyroid history, who came back 3 years after the introducing of amiodarone with major hyperthyroidism. After failure of medical treatment, a total thyroidectomy permitted to quickly stop hyperthyroidism and to early reintroduce amiodarone. Surgery seems to be the radical treatment when hyperthyroidism doesn't respond to the medical treatment and when the cardiopathy requires amiodarone.

The chloroquine is the mainly and most frequently drug used as antimalaric in the world, in spite of the extension of resistance phenomena. Besides, the chloroquine is also commonly indicated in rheumatology and dermatology as a chronic treatment of some connective tissue disease. The chloroquine has three main cardiovascular effect: membrane stabilizer, direct negative inotropic effect and direct arterial vasodilator. Thus, these cardiovascular iatrogenic effects of the chloroquine are important both through their potential frequency and seriousness. Personal clinical cases and medical review enables to identify the main effects, observed either with prophylactic, or curative, or even toxic dosages. The more often, there are some rhythm and conductance disorders, myocardiopathy, even sometimes vasoplegic shocks. A list of the commercial patent medicine including chloroquine enables to be aware, to prevent and to take into account the cardiovascular risks of a treatment newly set or carried on for long years.

While carotid sinus syndrome (CSS) is often suspected as a cause of syncope in the elderly, whether it represents an indication for cardiac pacing may remain uncertain. Bradycardia algorithms included in pacemakers are now able to establish a precise relationship between spontaneous asystole and occurrence of symptoms and strengthen the indication for permanent pacing. This study included seven men and three women (70.5 +/- 7.3 years of age) who, over an average period of 54.1 +/- 17 months, had suffered from syncope (12.6 episodes/patient) and presyncope (11.2 episodes/patient) attributed to pure cardioinhibition (2 patients) or mixed CSS (8 patients). Other sources of symptoms were excluded by thorough clinical evaluations, including Holter monitoring, echocardiography, and electrophysiological testing. All patients received a CHORUS 6234 pacemaker, the memory of which includes a dedicated bradycardia detection algorithm capable of storing atrial and ventricular chains, and date and time of the last ten pauses and/or bradycardic events. After a initial period of 14.7 +/- 8 months, during which symptoms were suppressed, the bradycardia algorithm was activated. From then on, a cumulative increase in the number of patients presenting with diurnal pauses was measured (1 month, n = 0; 3 months, n = 6; 9 months, n = 7; 2 years, n = 8). Fourteen episodes of diurnal asystole were recorded. The mean duration of the longest episodes of spontaneous ventricular standstill was 6,319 +/- 1,615 ms and was due to sinoatrial block (n = 7), atrioventricular block (n = 5), and a combination of both (n = 2). In conclusion, activation of the CHORUS bradycardia algorithm allowed confirmation of the appropriateness of permanent pacing in a majority of patients suffering from CSS.

If atrial sensing ability of a single-lead VDD pacemaker is well accepted at rest, the detection quality by atrial floating electrodes remains less recognized during exercise. The aim of this study was to verify, during treadmill test and a continous telemetry, the atrial tracking performance using four different leads technologies. From November 1994 to July 1997, 21 patients (71.3 +/- 6.3 years old, 7 female, cardiopathy: 57%) were paced for isolated high degree (permanent: 13, paroxystic: 8) AV block. The implanted devices were the Vitatron Saphir/Brillant lead (13 patients), Intermedics Unity/425/04-13 lead (5 patients), Pacesetter Addvent (2 patients), and Biotronik Eikos (1 patient). The acute atrial signal amplitude was 1.66 +/- 0.75 mV. The treadmill test used the chronotropic assessment exercise protocol after pacemaker reprogramming to detect atrial undersensing (AV delay < or = 120 ms, no hysteresis, no flywheel, upper rate increase). The mean delay was 31.1 weeks (range 1-100). The testing duration was 6.1 +/- 2.3 minutes, the number of steps was 3.3 +/- 1.3 per patient, and the peak exercise rate was 135 +/- 19 beats/min. At rest, complete atrial tracking was complete in 90% of the patients, and during testing in only 23.8% of the patients, while AV synchronization > 95% was present in 57.1%, > 90% in 71.4%, and > 85% in 90.4% of patients (Vitatron 13/13, Intermedics 3/5, Biotronik 1/1, and Pacesetter 1/2). During the recovery period synchronization was always > 95%. The mean P wave amplitude at rest was 1.1 +/- 0.5 mV; during the first step, 1.04 +/- 0.61 mV; second step, 0.94 +/- 0.53 mV; third step, 0.82 +/- 0.58 mV; fourth step, 0.67 +/- 0.39 mV; and during recovery, 1.13 +/- 0.67 mV. The mean P wave decrease signal at peak of exercise is 0.21 mV (from -1.31 to +0.5). In fact, P wave variations have several patterns: a decrease was measured in 7 patients, an increase in 2 patients, and no significant change in 7 patients. Single-lead VDD P wave identification during exercise was almost accurate. However, often there was progressive lowering of atrial sensing with transient loss of AV synchrony.

Absence of inferior vena cava (IVC) is an uncommon congenital abnormality with few clinical repercussions. We report the case of a 39 year old man with chronic pelvic pain, in whom a macroscopic hematuria episode occurring during exercise led to the discovery of an echographic pelvic venous stasis syndrome. Abdominal and pelvic computed tomography scanning then magnetic resonance imaging of inferior vena cava revealed absence of the postrenal segment of IVC with azygos continuation and considerable collateral venous derivations, leading to pelvic cavernoma.

A 58-year-old car driver suffered a road accident responsible for severe blunt thoraco-abdominal trauma. Transoephageal echocardiography, performed following the secondary development of a diastolic murmur, confirmed the presence of aortic incompetence due to commissural avulsion and guided the surgical treatment, which consisted of commissural suspension under cardiopulmonary bypass via a mini transverse trans-sternal incision. The rarity of acute aortic valve incompetence following non-penetrating thoracic trauma is illustrated by the data of the literature. This lesion is due to either avulsion of a sigmoid cusp or commissure, or laceration of the valvular tissue. Transthoracic echocardiography confirms the reality of aortic incompetence suggested clinically by appearance of a diastolic murmur, but confirmation of the mechanism of the lesions is based on transoesophageal echocardiography which allows perfectly safe and rapid visualization of the mechanism of the valvular lesion, investigation of associated lesions and guidance of therapeutic management.

If atrial vulnerability parameters are well defined, wavelength (WL) measurement (conduction velocity x refractory period), has never been assessed through an endocavitary electrophysiological exam. We investigated 30 patients (14 female, mean age 63.4 +/- 13 y.o.), 10 with paroxysmal atrial fibrillation (PAF group), 10 with ischemic cerebral injury (ICI group) by comparison with 10 controls (C group). The upper to lower right atrium conduction time and velocity were measured in the right atrium with a decapolar electrode catheter applied along the free wall. Others parameters correlated to atrial excitability were also taken into account: effective (ERP) and functional refractory periods (FRP); spontaneous or paced atrial electrogram (A1) or extrastimulated atrial electrogram (A2) widths, ERP/A2 ratio, provocative atrial testing. Measurements were taken in sinus rhythm and in 600-460 ms paced cycle lengths. If ERP, FRP, A1 widths are the same in the 3 groups, PAF and ICI groups have a significant increased conduction time and lower conduction velocity, leading to a shorter A1 WL during 600 and 460 ms paced rhythms (p < 0.05) and A2 WL during 460 ms paced rhythm. The provocative testing was positive in 60% of PAF and ICI groups, and there is a significant correlation between arrhythmia induction and 600 ms A1 WL or 460 ms A2 WL. This electrophysiological study suggests the possibility of an approach in humans of wavelength concept and proves the presence of correlation between a short wavelength and atrial spontaneous or induced arrhythmias. A no-arrhythmia band (A1 WL > 17 cm during 600 ms paced rhythm, A1 WL > 16 cm or A2 WL > 12 cm during 460 ms paced rhythm) and a fibrillation-band (A1 WL < 12 cm during 600 and 460 ms pacing, A2 WL < 7 cm during 460 ms pacing) can be defined. Therefore, the ICI group has the same atrial pattern as the AF group.

Clinical and biological pitfalls that lead to incorrect or delayed diagnoses of airport malaria are described based on 7 cases reported from the Paris region in the summer of 1994. We also report the outcome and the epidemiological features of these patients.

Infections after cardiac pacemaker implantation are rare (0.13 to 12.6%) but potentially severe complications. Staphylococcus is the genus most frequently isolated (72 to 100% of cases). The use of systematic prophylactic antibiotics remains controversial. From November 1991 to October 1993, 207 consecutive patients were submitted to a series of measures designed to reduce the risk of infection: a) intravenous bolus injection of Cefamindole, 15 minutes before implantation, b) cutaneous disinfection with iodinated polyvindone, c) injection of an ampoule of rifampin before closure of the pacemaker in the pouch, d) absence of drainage system. Patients were predominantly female (60.9%), with a mean age of 77 +/- 10 years, frequently suffering from heart disease (53.8%). The indication for implantation was atrioventricular block (39.7%), carotid sinus syndrome (27.5%), atrial arrhythmia (27.5%), resection of the node-His tract (5.3%). This procedure corresponded to the first implantation in 88.4% or replacement of a previous pacemaker in 11.6% of cases and the pacing mode was single-chamber (38.4% or replacement of a previous pacemaker in 11.6% of cases and the pacing mode was single-chamber (38.7%), or double chamber (61.3%). The mean duration of the procedure was 51.5 min +/- 30 min. The mean follow-up was 12.7 +/- 5 months. The overall mortality was 14% (11 cases of cardiac failure, 6 sudden deaths, 4 cerebrovascular accidents, 4 cases of pneumonia, 4 neoplasms). Only one infectious problem (endocarditis, i.e. 0.48%) was observed.

The carotid sinus syndrome is a well-known cause of syncope: the cardio-inhibitory forms are the easiest to diagnose and probably the easiest to treat. However, the vasodepressive forms are as common but their outcome is mainly unknown. Eight hundred and fifty-three patients underwent endocavitary electrophysiological studies with invasive blood pressure measurement for unexplained syncope between October 1984 and January 1990. A carotid sinus syndrome was diagnosed in 215 cases. Fifty-two patients (24.2%) had a cardio-inhibitory form (ventricular standstill > or = 3 s during carotid sinus massage), 40 (18.6%) had a pure vasodepressive form (isolated fall of systolic blood pressure > 50 mmHg during massage) and 123 patients (57.2%) had a mixed form. The average age was 74.1 +/- 9.7 years with no difference between the different forms. A number of parameters was different on the cardio-inhibitory and vasodepressive forms: the number of men (75.6 vas 24.4%; p < 0.05) and the number of syncopes (83.3 vs 60%; p < 0.02) were greater in the cardio-inhibitory form; the vasodepressive forms were more often associated with a history of transient ischaemic attacks (15 vs 0%), a poor cardiovascular status (hypertension: 47.5 vs 15.7%; p < 0.01), coronary artery disease (47.5 vs 25.5%; p < 0.05), cardiac failure (27.5 vs 11.7%; p < 0.05), induction of sustained supraventricular tachycardia (50 vs 23.5%; p < 0.05) and a greater pacemaker effect (53.6 vs 34.8 mmHg; p < 0.01); of the 191 patients (84.9% of the population) followed up for an average of 21.2 months, 168 received treatment: implantation of a cardiac pacemaker in 108 patients, reduction of antihypertensive and/or potentially bradycardia-inducing drugs in 30 patients, prescription of antiarrhythmic therapy, in 30 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

A 33-year-man with an encephalopathy of unknown aetiology, had an history of epilepsia for 30 years. Different types of seizures were seen, including grand mal and frontal attacks. Epilepsia was associated with mental retardation and behavioral disorders. At the age of 33, he was admitted for repetitive general convulsions. Epilepticus status lasted for two weeks and improved with vigabatrin et clonazepam. General seizures, frontal motor convulsions with arms and trunk antepulsion, and dacrystic attacks were seen. The latter seemed to be like normal crying because they were accompanied by lacrimation, contorted and mournful facies, and sobbing sounds. One year later, repetitive cardiac arrests occurred during a new epilepticus status. Cardiac arrests, observed on ECG holter lasted 10 to 24 seconds, without cardiac dysfunction. EEG patterns on ECG holter lasted 10 to 24 seconds, without cardiac dysfunction. EEG patterns included theta and delta activity with rhythmic slow wave epileptic activity, predominating on right side, in temporal areas. CT scan was normal. MRI showed right cerebral atrophy, prevailing in the temporo-mesial region, with right temporal horn enlargement. This case report of dacrystic seizures, the first one with MRI study, suggests that temporo-mesial structures of the non-dominant hemisphere may be involved in dacrystic and asystolic attacks.

The case of a 53-year-old patient with scapulo-humero-peroneal wasting, early flexion contractures of the elbows and ankles, abnormal cardiac conduction and probable X-related heredity is reported. Histology was suggestive of a primary and very slowly progressive muscular disorder. CT scan revealed fatty muscle degeneration which was more extensive than suggested by clinical findings. Electrophysiological studies revealed right atrial paralysis, left atrial tachycardia and supra and, above all, infra-His block. Sustained episodes of ventricular tachycardia, an anomaly described only rarely in pathology of this type, occurred some time after the fitting of a permanent pacemaker. The originality of this case of Emery-Dreifuss progressive muscular dystrophy lies in the usefulness of muscle CT scan and the existence of life-threatening arrhythmias.