Atteinte cardiaque dans la maladie de Lyme

Cardiac manifestations of Lyme Borreliosis are relatively infrequent, occurring within weeks after the infectious tick bite (median of 21 days), and resulting at this stage from a direct borrelial infection of the myocardium, as indicated by reports of spirochete isolation from pericardium and myocardium. They may persist or appear in the late, tertiary phase of the illness, being then more likely due to infection-triggered autoimmunity. Lyme carditis typically presents with a fluctuating degree of atrioventricular block that spontaneously resolves in several days. Rarely, myocarditis may occur with or without pericardial involvement, in patients presenting with chest pain, ST depression or T wave inversion, mimicking an acute myocardial infarction, and various arrhythmias are reported, as well as pericardial effusion or heart failure. A complete recovery is usually observed, spontaneous or after antibiotherapy. Severe myocarditis or Pericarditis leading to death is exceptional. The diagnosis of Lyme carditis is based on the same association of clinical and laboratory features as in Lyme disease without cardiac involvement. But the occurrence of conduction disturbances in healthy young people suggests screening for other criteria of Lyme disease. The management of Lyme carditis does not differ from the treatment of Lyme disease without carditis and is mainly based upon the use of doxycycline or ceftriaxone.

[Kawasaki disease is also a disease of adults: report of six cases]

Kawasaki disease is an inflammatory arterial disease of unknown cause usually affecting young children, the principal complication of which is coronary artery aneurysm. Early treatment with immunoglobulins and aspirin prevents this complication. The diagnosis requires expert clinical criteria and, in atypical forms, a more recent decisional diagnostic tree has to be used. The authors report 6 cases of adult Kawasaki disease. As in the other sixty or so cases in the literature, hepatic forms were the commonest (5/6). Only three of the six cases met the classical clinical criteria and the diagnosis was made by the decisional tree or after coronary complications in the oldest subject. The five treated patients progressed favourably after a course of immunoglobulins. Echocardiography detected 100% of children with coronary disease but it was more difficult in adults in whom new non-invasive methods of coronary imaging (fast CT and MRI) and stress testing should complete the investigations. The association of prolonged pyrexia, clinical criteria and a biological inflammatory syndrome should, after exclusion of the differential diagnoses, suggest a diagnosis of Kawasaki disease in the adult as in the child. The possibility of coronary disease, even though extremely rare, should be recognised by the cardiologist and lead to diagnostic and therapeutic managements as aggressive as in children.

[Implantation of mechanical pulmonary and tricuspid valve prostheses at a distance from complete repair of Tetralogy of Fallot]

The authors report the case of a 39 years old woman operated for tetralogy of Fallot at the age of 6. Multiple complications due to postoperative atrioventricular block and a poor surgical result on the pulmonary outflow tract led to several reoperations. Right ventricular dysfunction with pulmonary regurgitation and mitral tricuspid valve disease in a context of endocarditis on the pacing catheter led to double pulmonary and tricuspid valve replacement with mechanical prostheses. The outcome at follow-up at 3 years is good. To the authors' knowledge, this is the first reported case of double mechanical valve replacement of the right heart after complete repair of tetralogy of Fallot.

Intractable hiccup as the initial presenting feature of systemic lupus erythematosus

An infarctus of medulla oblongata was discovered in a 44-year old man with an intractable hiccup and 10, 11th and 12th right cranial nerves palsies. Systemic lupus erythematosus (SLE) with antiphospholipid syndrome was subsequently diagnosed. Hiccup has withdrew with corticosteroid therapy and low-dose aspirin. The other cases of literature and pathophysiologic hypotheses are briefly reported.

[Characterization of premature ventricular contraction initiating ventricular fibrillation]

The aim of this study is to characterize the electrocardiographic features of premature ventricular contractions (PVC) from different anatomical region that trigger ventricular fibrillation (VF).

METHODS AND RESULTS

36 consecutives patients (20 males, 42+/-14 yrs) undergoing VF ablation from 7 centres were studied (22 with idiopathic VF, 4 associated with a long QT syndrome, 3 with Brugada syndrome, 4 with ischaemic cardiomyopathy and 3 associated with other substrate). Mapping of these PVC showed 2 different origins, which were then confirmed by ablation: right ventricular outflow tract (RVOT) (22%) and peripheral Purkinje network (81%). One patient had PVC from both origins (Brugada). RVOT PVC were frequent but had triggered only 5+/-5 episodes of VF for 26+/-33 months. Purkinje PVC were more likely to be present during electrical storm with 18+/-28 episodes of VF for 33+/-45 months. Right Purkinje PVC have a left bundle branch block with superior axis morphology whereas left Purkinje ones have a right bundle branch block. The axis of activation showed variation from inferior to superior depending on the area of origin from the Purkinje network and the exit site to the myocardium. However Purkinje PVC were characterized by short QRS duration (126+/-18 vs 145+/-13ms for RVOT PVC; p=0.05). In addition the coupling interval was significantly shorter compared to RVOT PVC (292+/-45 vs 358+/-37ms respectively; p=0.005).

CONCLUSION

PVC initiating VF demonstrate specific electrocardiographic features that facilitate determination of their origin. Ablation of these typical PVC is feasible in order to reduce ICD shock.

[Sudden transformation of pulmonary stenosis to trilogy of Fallot in a 65 year old patient]

The authors report the case of a 64 year old woman with typical valvular pulmonary stenosis in whom spontaneous and sudden reopening of the foramen ovale resulted in cyanosis. Transthoracic echocardiography with injection of contrast provides a complete diagnosis: valvular pulmonary stenosis with a mean pressure gradient of 83 mmHg and massive right-to-left interatrial shunt. The malformation was treated by interventional catheterisation in a two-stage procedure: pulmonary valvuloplasty followed by closure of the foramen ovale because of the persistence of a right-to-left interatrial shunt. The functional improvement was followed by the appearance of effort angina. Coronary angiography showed single vessel disease of the left anterior descending artery treated by stenting. The long-term outcome was satisfactory.

[The place of telemedicine in rhythmology and cardiac pacing]

Rapid advancement in telecommunication technology has made possible automatic periodic transmission of pacemaker and implantable defibrillator data to the attending physician (home monitoring). Furthermore, technology using remote control software allows, through device programmers, interrogation of the device memory, permitting remote monitoring by physicians or technical support of the manufacturer. Potential applications of these two capabilities include a close watch over the functioning of the devices, ability to obtain an earlier diagnosis (and management) of arrhythmic events, and assistance at the time of implant procedure and routine follow up. Finally these new tools raise several questions concerning safety aspects (including reliability of transmission, encrypted transfer, restricted access of the central database), economic aspects, and physician and manufacturer's liability.

IRM et dysplasie arythmogène du ventricule droit (DAVD)

PURPOSE

To retrospectively evaluate the contribution of MRI to the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD).

PATIENTS AND METHODS

Thirty two men and 18 women (mean age: 48.7 years) were imaged using gated spin echo scans and short axis cine MR. References were McKenna criteria (gold standard), and also what we called "strong presumption" which may correspond to early or localized patterns, but correspond to negative McKenna scores.

RESULTS

One patient was claustrophobic; another one was lost to follow-up. In reference to McKenna score, diagnosis of ARVD was established in 12 patients (2 of whom had familial dilated biventricular cardiomyopathy with rhythmic expression). Sensitivity, specificity, positive predictive value, negative predictive value and prevalence were respectively: 75%, 75%, 50%, 90% and 25%. Using "strong presumption" criteria, we observed 14 true positives (with sensitivity of 82%, specificity of 87%, PPV of 78%, NPV of 90% and prevalence of 35%).

CONCLUSION

In our group, MRI was always performed before angiography. In our series, right ventricular wall T1W hyperintensity was the most frequent finding.

[Medullary extradural hematoma revealing a coarctation of the aorta]

The authors report a spontaneous, unusual complication of coarctation of the aorta. An 11 year old child was admitted for investigation of chest pain. Cardiovascular examination revealed typical clinical signs of coarctation of the aorta. Neurological examination found neck stiffness without headache or deficit. The presumptive diagnosis of dissection of the aorta was infirmed by echocardiography and MRI. The latter investigation, with views of the spinal cord, revealed a compressive medullary extradural haematoma. Antihypertensive therapy and corticosteroids with strict bed rest resulted in complete regression of the haematoma and the coarctation was operated 6 months later. Medullary complications of coarctation of the aorta are usually postoperative. Spontaneous complications are exceedingly rare but very serious: medullary compression by the dilated anterior spinal artery or rupture of an aneurysmal collateral vessel. In this case, magnetic resonance imaging led to diagnosis and effective early treatment of this complication before the patient developed a neurological deficit and the coarctation was treated surgically thereafter.

[Evaluation of a new stress echocardiography technique combining exercise and dobutamine in the detection of coronary disease]

Dobutamine stress echocardiography (DSE) and exercise stress echocardiography (ESE) are widely used for diagnosis of coronary artery disease. Each of these methods has limitations: secondary effects of Dobutamine, poor imaging quality, difficulty in attaining the maximal heart rate. The authors evaluated a test associating pedalling exercise at a constant low load (30-60 watts) with Dobutamine infusion (10-20-30-40 j/Kg/min +/- Atropine) (DES + E) in 42 patients referred for suspected coronary artery disease. All patients underwent coronary angiography on Day 1. There was significant coronary disease (> 50% stenosis) in 19 of the 42 patients. Sensitivity, specificity, negative predictive value, positive predictive value and overall diagnosis value were respectively 84, 87, 84, 87 and 86%. In the first 20 patients, the DES + E was compared directly with DES: There was only one undesirable side effect (hypertension) with DES + E compared with 5 with DES alone. The target heart rate was attained with lower doses of Dobutamine with DES + E (32.35 vs 39.42 j/Kg/min, p = 0.05). DES + E therefore seems to be a promising technique which is better tolerated than DES alone with very satisfactory diagnostic performances. However, these results require further confirmation in larger numbers of patients.

Predictive factors of ventricular fibrillation triggered by pause-dependent torsades de pointes associated with acquired long QT interval: role of QT dispersion and left ventricular function

INTRODUCTION

Death due to acquired torsades de pointes usually is caused by ventricular fibrillation (VF), but the contributing factors to VF triggered by pause-dependent torsades de pointes are not understood.

METHODS AND RESULTS

We evaluated 91 patients who fulfilled four criteria: (1) pause-dependent torsades de pointes; (2) prolonged QT interval and/or corrected QT (QTc) (>0.44 sec); (3) long-short initiation sequence; and (4) conditions known to induce pause-dependent torsades de pointes. There were 38 patients with a documented VF (group I) and 53 without VF (group II). Absolute and relative dispersions of QT and QTc were calculated based on the 12-lead standard ECG. Group I differed from group II with regard to myocardial infarction history (32% vs 13%; P = 0.035), left ventricular ejection fraction (44% +/- 14% vs 65% +/- 9%; P < 0.0001), presence of structural heart disease (100% vs 20.8%; P < 0.0001), QT mean (591 +/- 73 msec vs 514 +/- 78 msec; P < 0.0001), QTc mean (563 +/- 76 msec vs 508 +/- 90 msec; P = 0.002), absolute QT dispersion (166 +/- 56 msec vs 84 +/- 49 msec; P < 0.0001), relative QT dispersion (9.9% +/- 3.5% vs 6.3% +/- 3.2%; P < 0.0001), absolute QTc dispersion (158 +/- 57 msec vs 81 +/- 44 msec; P < 0.0001), and relative QTc dispersion (9.9% +/- 3.6% vs 6.2% +/- 3%; P < 0.0001). Multiple regression analysis showed that ejection fraction (P = 0.0001), presence of structural heart disease (P < 0.0001), and relative QTc dispersion (P = 0.038) were the only independent predictors of VF.

CONCLUSION

Left ventricular function, presence of structural heart disease, and QTc relative dispersion should be evaluated carefully in patients with conditions susceptible to inducing torsades de pointes.

[Syncope, conduction disorders. Controversial indications for cardiac stimulation]

The objective of permanent pacemaker implantation is to provide against an increased risk of death or to improve quality of life by abolishing symptoms. In both cases, certain indications for pacing have clearly demonstrated to be strongly beneficial in well selected patients, but other are still controversial, due to the lack of convincing and converging published data, or to the absence of general consensus among specialists, or because selection criteria for pacing have been poorly defined. We try to clarify when to pace or not to pace in such conditions as first degree AV block, type I second degree AV block, intracardiac conduction defects, including those occurring at the acute stage of myocardial infarct or after cardiac surgery, sick sinus syndrome in cardiac transplant recipients, carotid sinus syndrome, vasovagal syncope, and unexplained syncopes.

[Influence of alleles of apolipoprotein E on restenosis after coronary angioplasty in women]

Although coronary stenting reduces the incidence of post-angioplasty restenosis, it remains a problem. The influence of lipoproteins on the development of atherosclerosis has been demonstrated but their role in restenosis is controversial. Contradictory results have been published on the subject of the influence of the APO E genotype. In an initial study, the authors showed a closer correlation between Lp (a) and coronary artery disease in women than in men. A sub-group of women who underwent angioplasty and whose lipid profile had been well established, was analysed with respect to APO E alleles. The 59 patients who underwent angioplasty included 35 single, 20 twin and 4 triple vessel diseases. Control coronary angiography was performed in 40 of these women. A telephonic interview was carried out between 12 and 22 months after dilatation on the whole population. The apolipoproteins A1, B, Lp (a) and Lp A1 were measured by immunological, turbidimetric or electroimmunological techniques. The APO E genotyping was performed with the Inno-Lipa kit. The results showed 18 angiographic restenoses (Group A), 20 coronary artery disease without restenosis (Group B), 41 without angiographic (20) or clinical (21) restenosis (Group C). In Group A, the Lp (a) was well above the threshold value of 0.30 g/l. The e4 allele was associated with the highest values of total and LDL cholesterol fractions. There was no significant difference between the APO E genotype of the different groups or with respect to the severity of lesions. The authors conclude that if the e4 is more commonly associated with high LDL-cholesterol and Lp (a), its role in the process of restenosis remains unproven. A greater number of patients is required and further studies are desirable to determine the inflammatory and/or immunological mechanisms through which APO E could influence restenosis.

[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.

[Evaluation of cardiac risk before vascular surgery by dobutamine stress echocardiography]

The detection of coronary artery disease is essential before abdominal aortic surgery. In view of the limitations of the usual methods of investigation, dobutamine stress echocardiography was assessed in this indication. Eighty-five patients with an aortic abdominal aneurysm or obstructive arterial disease underwent dobutamine stress echocardiography followed by coronary angiography. Depending on the results, vascular surgery was performed directly, after myocardial revascularisation or not at all. Significant coronary lesions (stenosis > or = 50%) were found in 32 of the 85 patients (38%). Dobutamine stress echocardiography had a sensitivity of 78% and a specificity of 75%, and positive and negative predictive values of 66 and 85% respectively. The relative risk of coronary disease was 4.4. In this series, 15 patients had severe coronary lesions: 2 were turned down for surgery and 13 underwent myocardial revascularisation; 14 of them (93%) had a positive stress echo. The only 2 non-fatal cardiac complications of peripheral surgery (3%) occurred after a positive dobutamine stress echo. This study confirms both the necessity of preoperative assessment of coronary risk and the efficacy of dobutamine stress echocardiography in this indication. Dobutamine stress echocardiography is reliable, non-invasive, economical and a real alternative to isotopic methods. Its good predictive value justifies using coronary angiography only for patients with a positive result.

[Antiarrhythmic treatments of permanent atrial fibrillation]

The treatment of chronic atrial fibrillation has 3 different objectives: the control of the ventricular rate, the attempts to restore sinus rhythm, and the prevention of arrhythmia recurrences. Digitalis compounds, beta-adrenergic antagonists and calcium-channel blocking agents can be used to achieve reduction of the ventricular response, in recent-onset arrhythmia with rapid heart rate, and for long-term rate control in patients who cannot be converted to sinus rhythm. In some of them, a combination of 2 of these drugs is needed to slow the ventricular rate, at rest and on exertion. Sinus rhythm can be restored by direct-current cardioversion or by using various regimens of amiodarone, a type III antiarrhythmic drug, given orally or intravenously. Cardioversion might also be accomplished by type IA and IC antiarrhythmic drugs, including quinidine, flecainide and propafenone. However, proarrhythmic effects and haemodynamic deterioration are a major concern with these compounds. On the other hand the best indication of type IA and IC antiarrhythmic drugs is the control of arrhythmia recurrences; beta-blocking agents are highly effective in patients with a high sympathetic tone or hypertrophic cardiomyopathy. Finally the widespread use of amiodarone should be limited by its non-cardiac toxicity. Whatever the drug employed in the treatment of atrial fibrillation, monitoring the inotropic effect of the drug and the effect on cardiac conduction is mandatory.

[Prolonged decrease of prothrombin level caused by rodenticide poisoning. Apropos of 3 cases]

We report three cases of intoxication with anticoagulant rodenticides. This intoxication leads to prolonged hypocoagulability despite vitamin K therapy. In our patients, the side effect was present for 2 to 3 months.

Collective human food poisonings by clenbuterol residues in veal liver

Twenty-two patients were reported to complain of tremor, headaches, tachycardia and dizziness 1-3 h after eating veal liver. As clinical symptoms were not suggestive of an infectious cause, the presence of veterinary drug residues was suspected. Clenbuterol, a beta 2-agonist, was being illegally used in cattle because of its anabolizing properties and may explain the observed effects. Assays of clenbuterol in samples of veal liver showed concentrations of 0.375 and 0.500 micrograms/g. To our knowledge, this is one of the first reports of clinical symptoms in humans associated with the consumption of veterinary drug residue-containing food.

Improved dual chamber pacing mode in paroxysmal atrioventricular conduction disorders

Dual chamber pacing may sometimes be directly indicated for carotid sinus hypersensitivity, vasovagal syndrome, and certain cases of sinoatrial block and intermittent atrioventricular (AV) block, although AV conduction is dominantly normal. At times of normal AV conduction, competition between ventricular pacing and spontaneous ventricular depolarization may occur, with its adverse hemodynamic effects on ventricular function and unnecessary drainage of pacemaker battery energy. A new mode of stimulation is described, called automatic DDD mode, which functions in 'pseudo-AAI' mode during normal AV conduction and reverts to classical DDD function during episodes of AV blocks. Furthermore, during pseudo-AAI function, the pacemaker measures certain physiological parameters that serve to automatically program certain parameters used in DDD mode. Preliminary clinical evaluation has shown that this new mode functions satisfactorily.

Endless-loop tachycardias: description and first clinical results of a new fully automatic protection algorithm

Endless-loop tachycardia (ELT) is one of the most common pacemaker mediated tachycardia. An innovative ELT protection algorithm has proven to be clinically effective. A new improved version that will eliminate the need to program any parameter is now under clinical evaluation. Nine patients entered the study: six men and three women, aged 52 +/- 22 years. This automatic algorithm needs only 10 cycles to detect and confirm an ELT. Three hundred thirty-three ELTs lasting more than 9 cycles have been induced and analyzed. The total results are the following: mean duration: 6.7 sec +/- 3.1; mean ELT rate: 137 +/- 21.9 bpm, mean programmed upper rate limit (URL): 142.5 +/- 26.5 bpm (Only 70% of ELTs presented rates equal to programmed URL). (1) ELTs reduced by postventricular atrial refractory period (PVARP) extension on one cycle: 291 ELTs (87%). ELT rate: 128.5 +/- 18.2 bpm. (2) Retrograde block: algorithm operation may induce a retrograde block due to a short atrioventricular delay (AVD) applied during the confirmation phase to discriminate an ELT from a stable sinus rhythm. Thirty-two ELTs (10%) have been reduced and detected on a retrograde block occurrence. (3) Algorithm failure due to an unstable ventriculoatrial conduction time (VACT) even at fixed rate or to a retrograde Wenckebach behavior on AVD reduction during the confirmation phase. A total of 10 algorithms failed to detect or confirm an ELT have been recorded (3%). Mean duration: 8.2 +/- 4.2 sec, mean ELT rate: 148.9 +/- 14.3 bpm. This new fully automatic algorithm has reduced 97% of ELTs, including high rate episodes (100-175 bpm).(ABSTRACT TRUNCATED AT 250 WORDS)

[General physiopathology of chronic left ventricular insufficiency]

The failing heart is unable to provide some organs, notably the brain and the myocardium, with the amount of blood flow they require. To this myocardial inadequacy and resulting "circulatory insufficient" the body reacts by setting in action compensatory mechanisms which are "intracardiac" first (Starling's heterometric regulation, ventricular hypertrophy), then neurohormonal, with the activation of vasoconstrictor systems (noradrenergic system, renin-angiotensin-aldosterone system, arginine-vasopressin system) counterbalanced by the activation of vasodilator systems (vasodilator prostaglandins, atrial natriuretic factor and kinins). However, the vasoconstrictor systems outweigh the vasodilator systems. They create an excessive arterial and venous vasoconstriction, together with water-and-salt retention, which leads to an increase of left ventricular work during both systole and diastole and to a gradual worsening of the heart failure. The present-day treatment of heart failure aims at reducing the water-and-salt retention and at restoring the balance between the vasoconstrictor and vasodilator systems.

[Combination of slow-release diltiazem and a beta-blocker in arterial hypertension. 2 cases of cardiogenic shock with severe bradycardia]

Patient 1 received carteolol and captopril for hypertension. Three days after a slow-release diltiazem preparation (300 mg) had been introduced, he developed cardiogenic shock and sinus bradycardia (heart rate: 30/mn) with acidosis and severe hyperkaliemia. He was successfully treated by temporary pacing and dobutamine. Patient 2 had received sotalol and captopril for several years. Twelve hours after slow release diltiazem had been added, he was found in cardiogenic shock and extreme bradycardia with wide QRS, acidosis and hyperkaliemia. He died one hour later despite intensive emergency treatment. Concomitant use of beta-blockers and calcium channel blockers has been reported in patients suffering of severe coronary heart disease. However, several adverse reactions similar to our cases have been described. Slow-release diltiazem should be avoided in hypertensive patients taking beta-blockers.

[Potassium cyanide poisoning treated with hydroxocobalamin]

A fifteen-year-old girl, with a clean medical history, was admitted to the intensive care unit 90 minutes after ingestion of 2.5 g potassium cyanide. She had typical signs of severe cyanide poisoning including deep coma, circulatory failure, and major metabolic acidosis. Gastric lavage and antidotal treatment with 4 g hydroxocobalamin and 8 g sodium hyposulfite was administered without delay together with supportive treatment consisting of mechanical ventilation with FIO2, blood alkalinisation and administration of beta-stimulants. These measures led to a rapid clinical improvement. The ventilatory support was discontinued after 24 hours and the patient left the intensive care unit on the fourth day with only slightly impaired mental status. She survived despite a very high blood cyanide concentration (494 mumol.l-1 on admission) probably because of the rapid symptomatic and antidotal treatment.

[Acute intestinal occlusion and calcium antagonists]

A 41 years old male patient suffering from angina pectoris was treated with diltiazem (Tildiem). He was administered with nifedipine (Adalate) 3 times in succession and each time either complete or partial intestinal occlusion occurred. A laparotomy was carried out after the first occlusion, but no organic lesions were found. The search for an alternate non-drug related explanation proved negative. The most likely hypothesis is that of a direct relaxant activity on intestinal smooth muscle, which would explain the functional nature of the occlusion. Therefore it must be considered that the two drugs acted synergistically.

A new algorithm for a high level of protection against pacemaker-mediated tachycardia

Pacemaker-mediated tachycardia (PMT) is a well-known complication of DDD pacing. PMT needs a permeable V-A conduction and is usually initiated by a premature ventricular or atrial systole, artifact sensing, or misprogramming (long AV delay [AVD]). Today, protection against PMT is expected from pacemaker multiprogrammability. Unfortunately, this prevention is often ineffective; postventricular atrial refractory period (PVARP) must be prolonged, which limits the upper tracking rate and the patient capacity. The new Chorus ELA Medical DDD pacemaker provides classic protection against PMT (PVARP prolongation after premature V or A complex, magnet application, noise sensing), but also automatically reduces an eventual PMT and adjusts AVD or PVARP for a high level of protection. The process is divided in four steps: (1) a sensing step for 16 cycles, with V-P conduction analysis; (2) confirmation of the presence of the PMT and analysis of V-A conduction time; (3) a termination step, by extending the PVARP after the following ventricular heart beat; and (4) in case of immediate recurrence of the tachycardia, reprogramming of the AVD and eventually of the PVARP. By first reducing AVD, before reprogramming PVARP, the pacemaker preserves point 2:1, providing a higher exercise capacity. This algorithm was successfully tested in three patients who had a permeable V-A conduction, without any adverse effect.

Intracardiac ectopic thyroid

The case of a patient with an intracardiac ectopic thyroid is reported. A lesion was found in a 25-year-old man and was diagnosed by two-dimensional echocardiography as a right intraventricular tumor. An operation was performed. Histologic and ultrastructural studies showed that the tumor was a thyroid mass. The origin of intracardiac ectopic thyroids is probably to be found in disturbances occurring early in embryogenesis.

[Fatal poisoning by alcohol-free aniseed aperitif]

A case of chronic poisoning with alcohol-free "pastis" leading to the death of a 32 year old alcoholic patient is reported. The mean daily amount of ingested glycyrrhizinic acid was 0.35 g. "Torsades de pointes" secondary to severe hypokalemia were observed and prolonged cardiac arrest occurred. There was evidence of chronic hypokalemic myopathy and of rhabdomyolysis with acute renal failure. Furthermore, the origin of an associated cardiomyopathy is discussed.

[Myocobacterium tuberculosis endomyocarditis. Apropos of a case in a patient with a mitral valve prosthesis]

A case of lethal cardiac tuberculosis with myocardial and endocardial involvement is reported in a 46 year old man with a Starr-Edwards mitral valve prosthesis inserted two years previously for severe mitral regurgitation, secondary to ruptured chordae of the posterior mitral leaflet. Apart from tuberculous pericarditis, cardiac involvement is extremely rare; it occurs in "tuberculous septicemia" whose characteristic features--tuberculinic anergy, hematological abnormalities especially pancytopenia,--lead to delay in diagnosis, which is usually fatal. The case presented is an example.

[Intravenous isosorbide dinitrate in acute cardiac failure (author's transl)]

Isosorbide dinitrate (ISDN) was used by intravenous infusion in 7 patients with acute cardiac failure consecutive to acute (5) or chronic (1) myocardial infarction or to non-obstructive cardiomyopathy (1). Pulmonary artery pressure (PAP), pulmonary capillary pressure (PCP), right atrial pressure (RAP) and cardiac output were measured (PCP), right atrial pressure (RAP) and cardiac output were measured by intracardiac catheterization. The initial dosage of 2.5 mg/hour was increased until PCP was reduced to 15 mmHg or less or until troublesome side-effects developed. Control was achieved in 3 patients with doses of 2.5 to 7 mg/hour and, to a lesser extent, in one patient with up to 20 mg/hour. Three patients failed to respond even to higher doses and needed furosemide i.v. or furosemide + dobutamine. One patient died of cardiogenic shock. No changes in cardiac output, heart rate and blood pressure and no clinical side-effects were recorded. Thus, in acute cardiac failure ISDN may be effective in doses slightly superior to those of nitroglycerin, but increasing the dosage above 7 or 8 mg/hour does not bring additional benefits. The drug is remarkably well tolerated.

[Hemodynamic effects of intravenous isosorbide dinitrate in chronic heart failure (author's transl)]

During cardiac catheterization, isosorbite dinitrate (ISDN) was given intravenously to ten patients with confirmed left ventricular failure (10 NOMC, 1 ischemic cardiopathy, 1 valvular disease). When the left ventricular filling pressure was above 15 mmHg and the systemic systolic pressure exceeded 100 mmHg, a 500 gamma (first half of patients) or 800 gamma (second half of patients) bolus of ISDN was given intravenously, followed by an infusion of 2.5, 5 or 10 mg ISDN per hour. In all patients, the functional tolerance was excellent ; the heart rate remained unchanged and the systolic systemic pressure decreased only slightly (10 %). Left ventricular filling pressures returned to normal in four patients, decreased significantly in three, and remained unchanged in three. The cardiac output increased significantly in four patients. The poor initial hemodynamic conditions and the doses given, subsequently considered insufficient especially during the first part of the study, probably explain why ISDN was only partly effective.