[Aldosterone and its antagonists in heart failure]

THE ROLE OF ALDOSTERONE: Aldosterone is the key hormone in salt-water homeostasis. In heart failure, it participates in the appearance and maintenance of signs of congestion. Predominantly synthesised in the glomerular area of the cortico-adrenal glands, extra adrenal production areas have recently been identified notably in the brain, the heart and the large artery trunks. Aldosterone is activated in the cells by the intracellular mineral corticoid receptor. IN CARDIOVASCULAR-PATHOLOGIES: In chronic heart failure, patients treated with conversion enzyme inhibitor may escape from the renin-angiotensin blockade and this may lead to increased aldosterone plasma levels. This increase can induce not only vascular lesions and myocardial fibrosis but also renal and cerebral lesions.

THE EFFECTS OF SPIRONOLACTONE

In patients with NYHA stage III or IV heart failure, addition of spironolactone to the treatment with conversion enzyme inhibitor, diuretic and/or digitalis leads to a reduction in morbidity and mortality, as demonstrated in the RALES study. The mechanisms by which spironolactone has a beneficial effect remain discussed.

IN CLINICAL PRACTICE

The prescription of spironolactone is limited by hormonal side effects it provokes.

IN THE FUTURE

Eplerenone, a new competitive aldosterone receptor antagonist that appears to be devoid of such side effects and which, at least experimentally may well have the same beneficial effects, is presently under clinical assessment.

[Hospital mortality in cardiology. Analysis of deaths occurring in the Federation of Cardiology of a university hospital center]

The aim of this study was to examine the nature of cardiovascular deaths occurring in a University Hospital. All the hospital files of 1999 of the Federation of Cardiology of Henri Mondor Hospital, Creteil, of patients who died in the department or after transfer to the intensive care unit or cardiac surgery department, were analysed. Myocardial ischaemia was the leading cause of death, occurring either in the acute phase of transmural infarction or in patients with chronic cardiac failure. Deaths occurring during acute myocardial infarction were associated with late treatment and/or non-reperfusion of the culprit artery. The delay of diagnosis seemed to be secondary to late consultation or difficulty in diagnosis. This resulted in severe left ventricular dysfunction and, in a quarter of cases, mechanical complications. They led to the early death of the patients (2.9 +/- 3.5 days after admission). Campaigns of patient information and education of doctors who see these patients would seem to be the most appropriate approach to reduce the delay before hospital admission in order to reduce mortality related to myocardial infarction. Cardiac failure is a common cause of death in cardiology departments. The deaths of patients occurred after a long follow-up and several days after hospital admission (11 +/- 10 days). Optimisation of the treatment of cardiac failure, the investigation of ischaemic heart disease, the search for new therapeutic strategies of acute cardiac failure and information of patients about their disease, seem to be the principal measures to take to improve the poor prognosis of this disease.

[Hypertrophic obstructive cardiomyopathy and double-chamber pacing. Long-term results in a consecutive series of 22 patients]

The authors report their experience with dual-chamber pacing in hypertrophy obstructive cardiomyopathy. 22 patients (14 women and 8 men) mean age 60 +/- 13 years were implanted between 1992 and 1998. The criteria for pace-maker implantation were the presence of severe symptoms related with hypertrophy obstructive cardiomyopathy (dyspnea, angina, syncope) and left ventricular outflow tract gradient at mean 30 mmHg. Before pacing, all patients received a medical therapy which included beta-blockers or calcium inhibitors. This treatment was considered as ineffective or responsible of side effects. Patients were followed-up at mean 35.1 +/- 20.3 months. During this period, symptoms improved (mean NYHA class 2.7 +/- 0.5 before pacing vs 1.4 +/- 0.5 after pacing) and left ventricular outflow tract lowered from 95.4 +/- 40.8 to 39.3 +/- 20.5 at 6 months. 34.3 +/- 23.4 at one year and 26.5 +/- 21 at the end of follow-up. Seven patients had RF ablation of atrio-ventricular junction for paroxysmal atrial fibrillation or for lack of hemodynamic improvement with pacing. This procedure permits a significative lowering of gradient and a better ventricular filling. In conclusion, dual-chamber pacing is effective for treatment of hypertrophy obstructive cardiomyopathy when medical therapy is ineffective or bad tolerated at condition of: perfect pacing with permanent ventricular capture and optimal AV delay; RF ablation of AV junction in one third of cases; medical therapy systematically associated in all patients.

Prediction of functional recovery of viable myocardium after delayed revascularization in postinfarction patients: accuracy of dobutamine stress echocardiography and influence of long-term vessel patency

OBJECTIVES

We sought to evaluate dobutamine stress echocardiography (DSE) for predicting recovery of viable myocardium after revascularization with cineangiography as a gold standard for left ventricular (LV) function. We studied the influence of late vessel reocclusion on regional LV function.

BACKGROUND

Dobutamine stress echocardiography is a well established evaluation method for myocardial viability assessment. In previous studies the reference method for assessing LV recovery was echocardiography, long-term vessel patency has not been systematically addressed.

METHODS

Sixty-eight patients with a first acute myocardial infarction (AMI) and residual stenosis of the infarct related artery (IRA) underwent DSE (mean +/- standard deviation) 21 +/- 12 days after AMI to evaluate myocardial viability. Revascularization of the IRA was performed in 54 patients by angioplasty (n = 43) or bypass grafting (n = 11). Coronary angiography and LV cineangiography were repeated at four months to assess LV function and IRA patency.

RESULTS

Sensitivity and specificity of DSE for predicting myocardial recovery after revascularization were 83% and 82%. In the case of late IRA patency, specificity increased to 95%, whereas sensitivity remained unchanged. In the 16 patients with myocardial viability and late IRA patency, echocardiographic wall motion score index decreased after revascularization from 1.83 +/- 0.15 to 1.36 +/- 0.17 (p = 0.0001), and left ventricular ejection fraction (LVEF) increased from 0.52 +/- 0.06 to 0.57 +/- 0.06 (p = 0.0004), whereas in five patients, reocclusion of the IRA prevented improvement of segmental or global LV function despite initially viable myocardium.

CONCLUSIONS

Dobutamine stress echocardiography is reliable to predict recovery of viable myocardium after revascularization in postinfarction patients. Late reocclusion of the IRA may prevent LV recovery and influence the accuracy of DSE.

[Arterial hypertension due to compression of the renal artery, revealing ovarian cancer]

BACKGROUND

The etiologic work-up of hypertension with hyperaldosteronism and elevated serum renin includes search for renal artery stenosis. Intrinsic stenosis is a common finding, but hypertension secondary to extrinsic compression of the renal artery is exceptional.

CASE REPORT

A 48-year-old woman with an uneventful history was hospitalized for recent onset hypertension. Laboratory tests showed hypokaliemia, and elevated aldosterone and renin. Duplex Doppler exploration of the renal vessels evidenced extrinsic compression of the left renal artery by a tumoral mass found to be a nodal metastasis at surgery. Pathology reported cancer of the ovary. Blood pressure, and aldosterone and renin levels returned to normal after complete tumor resection. No antihypertensive treatment was required.

CONCLUSION

This is undoubtedly the first case of metastatic cancer of the ovary revealed by hypertension; it can be added to the list of 49 other published cases of extrinsic compression of the renal artery by various causes leading to hypertension. In most cases, surgical removal of the obstacle or nephrectomy provided cure of the hypertension.

[Myocardial viability. The concept of myocardial viability]

MYOCARDIAL VIABILITY

Certain zones of ischemic, akinetic or severely hypokinetic myocardium are capable of recovering normal contractile function. This is termed myocardial viability and occurs in two different situations: myocardial stunning and myocardial hibernation.

MYOCARDIAL STUNNING

This term designates temporary but prolonged impairment of myocardial function resulting from a brief episode of ischemia before reperfusion.

MYOCARDIAL HIBERNATION

Hibernation designates prolonged but potentially reversible myocardial contractile dysfunction caused by chronic myocardial ischemia and persisting at least until blood flow is restored.

CLINICAL CONSEQUENCES

Theoretically reversible, myocardial stunning or hibernation can have devastating effects if they persist too long. Revascularization with angioplasty or bypass surgery is indicated.

DIAGNOSIS

The degree of myocardial viability in akinetic zones can be determined by assessing preserved inotropic capacity with stress echocardiography and/or evidencing metabolic activity with isotopic techniques (myocardial scintigraphy, positron emission tomography).

Is left atrial appendage flow a predictor for outcome of cardioversion of nonvalvular atrial fibrillation? A transthroacic and transesophageal echocardiographic study

Accurate echocardiographic parameters for predicting the success of cardioversion or maintenance of sinus rhythm are poorly defined. This prospective transthoracic and transesophageal echocardiographic study was conducted to test the hypothesis that the left atrial appendage flow pattern could be a predictive parameter of the success of cardioversion and maintenance of sinus rhythm in patients with nonvalvular atrial fibrillation. Eighty-two consecutive patients with nonvalvular atrial fibrillation of <6 months' duration underwent transesophageal examination after transthoracic echocardiography. After exclusion of left atrial thrombus, pharmacologic (n = 18) or electrical (n = 64) cardioversion was successful in 75 of 82 patients. In the group that underwent successful cardioversion, maintenance of sinus rhythm (n = 35) or recurrence of arrhythmia (n = 40) was assessed during a 1-year follow-up. During transesophageal examination, five left atrial appendage thrombi were found, spontaneous echo contrast was present in 26 (32%) patients, and mean peak left atrial appendage emptying velocity was 35 +/- 18 cm/sec. Peak left atrial appendage emptying velocity was found to be statistically related to parameters of left ventricular and left atrial function but not to long-term maintenance of sinus rhythm. No other echocardiographic parameter was identified as a predictor for either the success of cardioversion or the maintenance of sinus rhythm at follow-up. In patients with nonvalvular atrial fibrillation of recent onset, peak left atrial appendage emptying velocity appears to be a complex parameter depending on left atrial and left ventricular function but that does not predict either the success rate of cardioversion or long-term maintenance of sinus rhythm after successful cardioversion.

[Echocardiographic factors predicting the maintenance of sinus rhythm one year after cardioversion for non-valvular atrial arrhythmias]

Echocardiographic factors predictive of the maintenance of sinus rhythm after successful cardioversion were investigated in 94 patients with non-valvular atrial arrhythmias of recent onset. Seventy-five patients with atrial fibrillation and 19 with atrial flutter admitted for reduction of their arrhythmias underwent transthoracic and transoesophageal echocardiography. After excluding a thrombus in the left atrial appendage or checking that it had disappeared (5 patients), and electrical (n = 74) or pharmacological (n = 20) cardioversion was successfully performed. The maintenance of sinus rhythm (n = 44) or recurrence of arrhythmia (n = 50) were controlled every 3 months for one year. The mean value of the peak positive blood flow in the left atrial appendage was 38 +/- 20 cm/s for the whole group. It was not possible to identify an echocardiographic parameter predictive of maintenance of sinus rhythm at one year either in the whole group or in the subgroups with atrial flutter or atrial fibrillation. In the group in atrial flutter, the mean value of the peak positive blood flow in the left atrial appendage was significantly greater than in the group with atrial fibrillation: 49 +/- 22 cm/s vs 35 +/- 18 cm/s, respectively; p < 0.05. The peak of positive flow in the left atrial appendage was statistically related to indirect parameters of left atrial function and of left ventricular function in the group with atrial fibrillation but only with parameters of left ventricular function in the smaller group with atrial flutter.

Chronic irregular idiopathic ventricular tachycardia with myocardial dysfunction suppressed by verapamil in an adult

We report a case of an almost permanent ventricular tachycardia that occurred in a 39-year-old man a few weeks before admission to the hospital. This arrhythmia was noticeable by its total irregularity and its association with a left ventricular dysfunction. The precise nosological frame for the arrhythmia was difficult to define. This case presented as an idiopathic left ventricular tachycardia, the features of which could be consistent with an atypical parasystole. The rapid abolition of the rhythm disturbance by oral verapamil without recurrence at 6 months resulted in normalization of the contractile function.

[Myocardial infarction and effort rhabdomyolysis. Problems caused by serum enzymatic assays]

The authors report the case of a patient who presented with myocardial infarction and rhabdomyolysis. The mild ECG changes in the basal leads and the normal MB creatinine phosphokinase fraction, expressed as a percentage of total CPK, delayed the diagnosis of myocardial infarction. The presence of a rhabdomyolysis without any clinical manifestation was suspected from the severe and prolonged increase in cardiac enzyme levels. Contrary to the usual method of measuring the MB fraction of CPK by immuno-inhibition, the fluorimetric immuno-enzymological technique enabled diagnosis of the infero-lateral-basal infarct, later confirmed by echocardiography and left ventriculography. This new technique would seem to be very useful, given the high sensitivity and specificity and its rapidity not only in the context of myocardial infarction associated with rhabdomyolysis, but also in the frontier forms of unstable angina and definitive myocardial infarction.

[Hemodynamic study of intravenous milrinone in 26 patients with NYHA class III or IV cardiac failure]

The hemodynamic effects of milrinone (WIN 47203) were studied in 26 NYHA Class III or IV patients. The compound was administered intravenously using a protocol including an initial push dose of 50 micrograms/kg in 10 min, followed by a 24 hour infusion at the dose of 0.5 microgram/kg/min. Maximal response was obtained after 15 min and persisted during the infusion: cardiac index increased from 2.08 +/- 0.36 l/min/m2 to 3.09 +/- 0.68 l/min/m2, while capillary pressure fell from 25 mmHg to 16-17 mmHg. These variations were significant (p = 0.01). Heart rate was stable. Mean peripheral blood pressure fell modestly (6%). Systemic vascular resistance fell by 30% and pulmonary vascular resistance by 20%. All these results confirmed the beneficial effect of this inotropic agent administered intravenously. The increase in ventricular premature contractions noted by many justifies the careful surveillance of these patients by monitoring.