Effects of diastolic synchronized retroperfusion on regional coronary blood flow in experimental myocardial ischemia.
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Animals↗
Biomedical subjects
J Bardet
Publications and source records attributed to J Bardet.
[Value of continuous electrocardiographic recording using the Holter method in the diagnosis and surveillance of myocardial ischemia].
A series of 80 patients underwent continuous electrocardiography by Holter monitoring (ECG-H) for 24 hours to detect myocardial ischaemia. Fifty five patients were not on anti anginal therapy. The results of ECG-H were compared with those of exercise electrocardiography (ECG-E) (33 cases) and coronary angiography (50 cases). The ECG-H was positive in 31 of 43 patients (72%) with clinical (5 patients) or angiographic (38 patients) signs of ischaemic heart disease. The ECG-H was negative in 11 out of 12 patients (92%) with normal coronary; angiography. The sensitivity and specificity of ECG-H (57% and 92%) were inferior to those of ECG-E (75% and 100%) in the 33 untreated patients undergoing all three investigations. Twenty five recordings were compared with the ECG-E to assess anti anginal therapy. In asymptomatic patients ECG-H showed pathological ST depression in 10 cases, the ECG-E being positive in 1 7 cases. Anginal chest pain was induced on ECG-E in 5 out of 7 cases with a positive ECG-E and negative ECG-H. The lower sensitivity of the ECG-H compared to the ECG-E is related to several factors: 1) the sensitivity of the ECG-E increases with the number of exploratory electrodes; 2) reduced levels of physical activity decrease the sensitivity; in false negative cases the heart rate on ECG-H was only 74 +/- 7% of that corresponding to the threshold of positivity of the ECG-E, compared to 97 +/- 16% of the threshold heart rate in true positives (p less than 0,001); 3) the sensitivity of the ECG-H and ECG-E depends on the severity and distribution of the coronary lesions; false negative results were commoner in single vessel disease (57%) than in double or triple vessel disease (24%) (p less than 0,01). Anginal pain during the test increased the sensitivity to 92%. The specificity of the ECG-H is partially dependent on the recognition of positional variations of the ST segment. These were observed in 10% of cases but were generally easy to distinguish by their beat-to-beat appearances. The satisfactory specificity of the ECG-H in this study is also related to the high incidence of coronary artery disease in the population under study (80%). The predictive value of a positive test (Bayes theorem) was 97%, but that of a negative test was only 41%.
Adult↗
[Quantitative semi-automatic analysis of the M mode echocardiogram].
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Automation↗
[Peripheral effects of nitrate compounds (author's transl)].
Nitroglycerin primarily acts on smooth muscle fibers, and this effect is dose-dependent. High doses seem to affect mainly coronary blood flow; moderate doses act on both systemic arterial blood flow (resistance vascular bed) and return venous blood flow (capacitance vascular bed), while low doses influence only the latter. These various modes of action account for the discrepancies observed between the results of experimental studies, the final effect being the algebraical resultant of combined individual actions. In coronary insufficiency, where treatment aims at reducing myocardial oxygen consumption without lowering coronary perfusion pressure, nitroglycerin should be given in low doses. In congestive heart failure, where the primary target is reduction in preload and, consequently, heart work without excessive reduction in afterload that would result in decreased stroke index through Frank-Starling's mechanism, a detailed knowledge of the physiological mechanisms involved is required to guide nitroglycerin treatment.
Angina Pectoris↗
[Prolonged hemodynamic effects of a nitroglycerin microcapsule preparation administed orally (author's transl)].
The hemodynamic effects of a microcapsule nitroglycerin preparation (Lénitral) were studied in 30 patients. Ten patients received 2 capsules of Lénitral 2,5 mg equivalent to 5 mg nitroglycerin; ten patients received 1 capsule of Lénitral 7,5 mg equivalent to 7,5 mg nitroglycerin, and ten patients received a placebo. Central venous pressure (CVP), systemic arterial pressure (AP) and heart rate (HR) were monitored during 12 hours. In the two groups treated, there was a significant decrease in CVP, starting 30 minutes after administration, lasting until the 8th hour and followed by a gradual increase; HR remained unaltered. AP was only lowered in patients under Lénitral 7,5 mg. There were no changes in these parameters among patients under placebo. In addition, 10 patients were catheterized one hour after oral administration of either 2 capsules of Lénitral 2,5 mg or a placebo. In the patients treated there was a significant decrease in right and left ventricles filling pressure, without changes in HR, AP, cardiac index and peripheral systemic resistances. At the end of the study, administration of 0,6 mg sublingual nitroglycerin produced no further changes in these parameters, in contrast with patients under placebo. The study indicates that Lénitral exerts prolonged hemodynamic effects and that low doses act primarily on preload and higher doses on both preload and afterload. This makes Lénitral a valuable drug for long-term treatment of chronic coronary disease and congestive heart failure.
Administration, Oral↗
Two dimensional echocardiographic visualization of ventricular septal rupture after acute anterior myocardial infarction.
In three consecutive cases of ventricular septal rupture after acute anterior myocardial infarction, wide angle two dimensional echocardiography readily visualized the septal defect, permitting the defect to be localized and its size estimated. In addition, negative contrast echoventriculography identified a left to right shunt at the ventricular level. The echocardiographic findings were corroborated by cardiac catheterization data in all patients, by perioperative examination in two and by postmortem findings in one patient. Postoperative echocardiographic studies afforded demonstration of the patch closing the defect. In patients with acute myocardial infarction associated with the sudden appearance of a systolic murmur, two dimensional echocardiography should be performed promptly in order to guide the diagnosis and management of these critically ill patients. In some patients with severe cardiogenic shock, in whom a favorable prognosis depends on rapid treatment, two dimensional echocardiography may allow the patient to be taken to surgery immediately without further study.
Aged↗
[Emergency diagnosis by two-dimensional echocardiography of septal rupture secondary to acute myocardial infarction. Apropos of 7 cases].
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Aged↗
New catheter-pump system for diastolic synchronized coronary sinus retroperfusion.
Coronary retroperfusion with the object of delivering oxygenated blood to the ischemic myocardium might be defined as the process of withdrawing blood from a systemic artery and reinjecting it into the coronary sinus. A diastolic synchronized retroperfusion catheter-pump system is presented and feasibility of achieving retrograde infusion of arterial blood was tested. An autoinflatable bladder catheter was specially designed to compartmentalize the coronary sinus at onset of diastole and insure unidirectional retrograde infusion of arterial blood. Bladder deflation at onset of systole allowed coronary venous drainage. Actuation of the retroperfusion bladder catheter was obtained from an electropneumatic console triggered by the electrocardiogram. In vitro and animal studies indicate that this system converted the natural (steady) arteriovenous shunt flow into an artificially pulsed shunt flow, with maximal positive flow in diastole and trivial negative flow in systole but did not alter absolute magnitude of shunt flow. Thus, diastolic synchronized retroperfusion of arterial blood through the coronary sinus may provide temporary protection from acute myocardial ischemia.
Animals↗
Prolonged hemodynamic effects (12 hours) of orally administered sustained-release nitroglycerin.
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Administration, Oral↗
Reversibility of alcoholic cardiomyopathy with abstention from alcohol.
A 46-year-old chronic alcoholic patient with typical and severe congestive cardiomyopathy was studied hemodynamically on two separate occasions. The second study followed after a 1 1/2-year period of virtually complete abstention from alcohol and revealed that the left ventricular dysfunction had disappeared. Depsite persisting atrial fibrillation, the response to moderate exercise and to plasma volume expansion was within the normal range. When last seen, 29 months after initial hospitalization, the patient was symptom-free and was not given any treatment.
Cardiomyopathy, Alcoholic↗
Regional left ventricular function assessed by contrast angiography in acute myocardial infarction.
The relationship of segmental left ventricular (LV) wall motion abnormalities to LV function 2-6 days after acute transmural myocardial infarction (MI) was investigated in 45 patients by quantitative contrast ventriculography. Patients were divided into four classes according to the MIRU criteria. Segmental wall motion was assessed by determining the percentage of systolic shortening (deltaS) along nine hemiaxes and the extent of akinetic or dyskinetic abnormally contracting segments (% ACS) expressed as a percentage of end-diastolic perimeter. When compared with that in 17 normal control-subjects, the LV end-diastolic volume was increased only in patients in class III and class IV; the LV end-systolic volume increased progressively from normal through class IV. Ejection fraction had a negative linear correlation with %ACS (r = 0.97). The size of ACS was larger in anterior (34 +/- 14%) than in inferior MIs (23 +/- 7%), resulting in greater LV dysfunction. However, for a comparable size of ACS, infarct location alone did not influence LV function parameters. In the noninfarcted zone, deltaS was increased when the size of ACS was less than 25% and reduced when the size of ACS was greater than 25%. Thus, the size of ACS is a major determinant of LV dysfunction in acute MI. The compensatory mechanisms operate either through an augmented mechanical function of residual myocardium when the infarct is small, or through the Frank-Starling mechanism when the infarct is large.
Angiocardiography↗
[Left ventricular cineangiography in the convalescent phase of a 1st myocardial infarct. Influence of coronary lesions].
80 patients with a primary myocardial infarction (32 anterior and 48 posterior) underwent cardiac catheterisation and angiography (coronary arteriography and selective left ventricular cineangiography) within 12 months of infarction. Analysis of the results of catheterisation and angiography showed: -- Diffuse coronary artery narrowing to be more frequent in patients with posterior infarction. Significant stenosis of the left anterior descending artery was observed in half these cases; -- No correlation between the results of cardiac catheterisation and the distribution of the coronary artery lesions. Changes of ventricular contraction are essentially related to the infarct size and much less to the quality of the healthy myocardium as far as can be appreciated by the usual haemodynamic methods in both anterior and posterior myocardial infarction.
Adult↗
[Average steady-state plasma levels with slow release quinidine preparations].
Arabogalactane sulphate of quinidine (AGSQ) is a slow release preparation of quinidine. The aim of this study was to compare the plasma levels of quinidine obtained by different preparations of AGSQ (AGSQ I, II and III) and to determine which was best suited to therapeutics. The "in vitro" study showed different amounts of quinidine liberated in 6 hours, 34% with AGSQ I, 58% with AGSQ II and 100% with AGSQ III. The plasma quinidine levels were studied after administration of a dose corresponding to 330 mg quinidine base, morning and evening for 7 consecutive days to 27 hospitalised patients; 7 received AGSQ I, 11 received AGSQ II 5, received AGSQ III and 4 quinidine sulphate. The delay in reaching a steady state was 24 hours for the quinidine sulphate 36 hours for AGSQ I, 48 hours for AGSQ II and 60 hours for AGSQ III. The average plasma level on the 7th day (Cee) was 2.74 +/- 0.71 microgram/ml, 2.62 +/- 0.74 microgram/ml and 3.29 +/- 0.72 microgram/ml respectively. The plasma quinidine levels were maintained between toxic and therapeutic levels (3,5 and 1,7 microgram/ml) only with AGSQ II by suppressing the peak observed 1 hour administration of quinidine sulphate. An excellent correlation (r = 0,984) was observed between the plasma quinidine 6 hours after ingestion and the Cee. A blood test during the steady state, 6 hours after ingestion of the drug, is useful in adjusting the dosage. These results suggest that AGSQ II is the preparation best suited for therapeutic usage although it does not give the best relative bioavailability of the drug.
Delayed-Action Preparations↗
Treatment of early postinfarction ventricular aneurysm by intra-aortic balloon pumping and surgery.
In nine patients with medically refractory left ventricular failure and/or ventricular arrhythmias, secondary to acute formation of a ventricular aneurysm, intra-aortic balloon pumping (IABP) was instituted 24 to 36 hours before diagnostic angiographic studies. Ventricular irritability was reduced and heart failure was controlled in all patients. Eight patients underwent operation, four within 3 weeks of an acute myocardial infarction and four within 3 months. All had resection of the recent infarction and two had myocardial revascularization as well. Two of the eight patients died in the early postoperative period from intractable ventricular fibrillation. All six patients who survived the operation (mean follow-up 12 months) had excellent clinical results. Ventricular irritability was suppressed and only one patient had residual heart failure. However, there was one late death 7 months after operation. The results suggest that surgical therapy may be effective in the management of medically unresponsive arrhythmias and/or congestive heart failure in the acute or intermediate postinfarction phase. IABP assistance was helpful in supporting the circulation and reducing ventricular irritability during the preoperative and postoperative periods.
Aged↗
Clinical assessment of infarct size by serial determinations of serum creatine phosphokinase activity.
Infarct size (IS) was estimated from serial total creatine phosphokinase (CK) changes in 82 patients with acute myocardial infarction (MI). Anteroseptal and inferior MI involved a relatively small mass of myocardium (16.0 +/- 6.4 and 24.7 +/- 10.0 CK-g-eq respectively); anteroapical and inferoposterior MI had an average IS of 35.9 +/- 15.9 and 32.8 +/- 13.8 CK-g-eq respectively (NS); extensive anterior and inferoposterolateral MI had an average IS of 57.8 +/- 20.1 and 51.1 +/- 11.5 CK-g-eq respectively (NS). Left ventricular failure (LVF) correlated with estimated IS and not with location of the infarct. In patients with an IS ranging from 30 to 50 CK-g-eq, the incidence of LVF was 33%. In patients with an IS greater than 50 CK-g-eq, the incidence of LVF was 65%. Out of the 6 patients who died, 3 had an IS greater than 60 CK-g-eq. 3 groups of patients could be identified from the duration of the CK release time: in group I (mean = 20 +/l h; n = 61), infarct size was highly correlated with peak CK activity (r = 0.93); in group II (mean = 39 +/- 7 h; n = 17) the correlation between IS and peak CK activity was poor (r = 0.59) and might indicate a gradual necrosis; in group III (n = 4) patients with reinfarction showed a second peak on the descending limb of the CK activity curve. Follow-up information was available in 96% of the 76 survivors. At the end of the follow-up (18.1 +/- 10.8 mth) IS was not significantly different in patients with LVF (42.7 +/- 17.5 CK-g-eq) and in those without LVF (34.7 +/- 19.7 CK-g-eq).
Adult↗
Mechanical circulatory assistance by intra-aortic balloon pumping for the treatment of cardiogenic shock.
Although the shock state due to acute myocardial infarction may be reversed by IABP in 80 per cent of patients, 55 to 65 per cent remain balloon-dependent. Therefore some attempt to correct the underlying anatomic abnormalities (reversible ischaemic areas and/or mechanical defects) appears necessary if these patients are to survive. With IABP catheterization studies performed in these critically-ill patients are well tolerated. Myocardial depression after cardiopulmonary by-pass is often related to subendocardial ischaemia. The combination of IABP and surgery has resulted in survival of approximately 50 per cent of patients in cardiogenic shock secondary either to a mechanical defect complicating myocardial infarction or to open-heart surgery.
Assisted Circulation↗
[Surgical treatment by valve replacement and aorto-coronary bypass in mitral valve insufficiency caused by chronic dysfunction of the posterior papillary muscle].
Nine patients with cardiac failure which was refractory to medical treatment, and which was caused by chronic malfunction of the posterior papillary muscle, as a result of a myocardial infarction, were studied by cardiac catheterisation and coronary arteriography. The mean pulmonary capillary pressure was 31+/-16 mm of mercury with a nu wave at 51+/-27 mm of mercury. The end diastolic volume was increased (141+/-68 ml/m2) and the ejection fraction lowered (0.40+/-0.13). The left ventricle had overall hypokinesia in 5 patients and akinesia of the inferior wall, representing 21+/-24% of the end diastolic perimeter, in 3 others. All these patients had significant lesions of two or three of the main coronary trunks. At operation lengthening of the posterior papillary muscle and/or the cordae was found. All patients had a replacement mitral valve of the Starr-Edwards type, associated with an aorto-coronary bypass of the anterior descending artery. The operative mortality was zero. At a mean follow-up period of 21 months, there had been no late death, and all the patients were improved.
Aged↗
[Effort electrocardiography and coronary arteriography following a 1st myocardial infarction. Critical study of the effort test].
Sixty-five patients, convalescent from a first myocardial infarction (anterior in 24 cases; inferior in 41 cases), underwent an effort electrocardiogram on a treadmill and coronary arteriography. In the anterior infarcts, coronary arteriography showed single vessel disease (anterior descending artery) in 54% of cases and double or triple vessel disease in the others. The effort test was positive in only 25% of patients with an anterior infarct. The presence of stenotic lesions of the circumflex artery and/or right coronary artery was unsuspected in 63% of patients. In the inferior infarcts, there was a significant stenosis of the anterior descending artery in 51% of the cases. The effort test was positive in 54% of patients and in 77% of those the anterior descending artery showed a significant stenosis. The appearance (or increase) of ST elevation greater than or equal to 1 mm in the leads facing the infarcted zone was an indication of more severe deterioration in left ventricular function as shown by a more marked reduction in ejection fraction and a more extensive akinetic region. The co-existence of ST elevation in the leads facing the infarcted zone and of ST depression greater than or equal to 1 mm in the reciprocal leads always indicated that another major vessel was involved, but this was only found in 25% of cases in this series.
Angiography↗