Biomedical subjects
X Bosch
Publications and source records attributed to X Bosch.
Comparison of clinical variables and variables derived from a limited predischarge exercise test as predictors of early and late mortality after myocardial infarction.
An exercise test limited to 5 METS or 70% of age-predicted maximal heart rate was performed 1 day before hospital discharge by 225 survivors of acute myocardial infarction, all of whom were subsequently followed up for at least 5 years. The mortality rate was 11.1% during the first year, but averaged only 2.9% per year from the second to fifth year. Over the entire follow-up period, the five variables that predicted mortality by multivariate analysis were QRS score, an exercise-induced ST segment shift, previous infarction, failure to achieve target heart rate or work load and ventricular arrhythmia during the exercise test. Because mortality differed markedly before and after 1 year, Cox regression analyses were performed separately for both of these periods. The factors that were predictive of mortality during the first year were an exercise-induced ST shift (p less than 0.0001, relative risk 7.8), failure to increase systolic blood pressure by 10 mm Hg or more during exercise (p = 0.0039, relative risk 4.3) and angina in hospital 48 hours or longer after admission (p = 0.0046, relative risk 3.4). None of these three variables was predictive of mortality after 1 year. Previous infarction (p = 0.0007), QRS score (p = 0.0042) and ventricular arrhythmia during the exercise test (p = 0.016) were predictive of mortality after the first year. Thus, clinical and exercise test variables are complementary predictors of mortality after myocardial infarction. An abnormal ST segment response during an early limited exercise test and angina in the hospital are common strong predictors of mortality to 1 year, but not thereafter. Late mortality correlates with markers of poor left ventricular function.
Coronary angiographic significance of left anterior fascicular block during acute myocardial infarction.
The clinical and angiographic significance of isolated left anterior fascicular block occurring during the early stage of acute myocardial infarction was studied in 141 consecutive patients who underwent cardiac catheterization before hospital discharge. Left anterior fascicular block occurred in 15 of the 62 patients with an anterior wall infarction and in 13 of the 79 with an inferior infarction. None of the clinical characteristics differed among patients with or without left anterior fascicular block. The number of coronary vessels with significant stenosis, the Friesinger and the Gensini scores for severity of stenosis and the ejection fraction were also similar in the two groups. Patients with left anterior fascicular block had more severe narrowing of the coronary artery supplying the infarct zone (88 +/- 21 versus 70 +/- 35%, p less than 0.001) and tended to have less developed collateral circulation (collateral score 0.7 +/- 0.8 versus 1 +/- 0.8, p = 0.10). A significant stenosis of the left anterior descending coronary artery was found as frequently in patients with as in those without left anterior fascicular block (64 versus 65%); 29% of the patients with inferior wall infarction and left anterior fascicular block had left anterior descending coronary artery stenosis compared with 47% of the patients without this conduction disturbance (no significant difference). When the infarction was located anteriorly, a significant stenosis of the proximal segment of the left anterior descending coronary artery was present in 47% of the patients with and in 45% of the patients without left anterior fascicular block.(ABSTRACT TRUNCATED AT 250 WORDS)
Clinical and angiographic assessment 6 months after double vessel percutaneous coronary angioplasty.
Percutaneous transluminal coronary angioplasty is an accepted treatment for selected patients with single vessel disease but has not been rigorously evaluated in patients with double vessel disease. Among 769 patients undergoing transluminal coronary angioplasty between 1980 and 1984, 74 with double vessel stenosis of 50% or more underwent double vessel coronary angioplasty. Primary success was obtained for both lesions in 63 patients (85%), for one lesion in 11 patients (15%) and for 137 (93%) of 148 segments overall. Except for myocardial infarction in one patient, no serious complication occurred. Before coronary angioplasty, 15 patients had unstable angina, 14 had Canadian Cardiovascular Society class III and 32 class I to II effort angina and only 2 were asymptomatic. Six months after coronary angioplasty, 27 were asymptomatic, 27 had class I to II and 5 had class III effort angina and 2 had sustained an episode of unstable angina. During the follow-up study, two patients had an infarction and one had coronary artery bypass surgery. Coronary arteriography was performed at a mean of 5.5 +/- 2.1 months after coronary angioplasty in all but three patients. Restenosis was found in 30 (23%) of 132 segments with angiographic control. Restenosis was present in one vessel in 17 patients and in both vessels in 4; 40 patients (66%) had no restenosis. Of the 34 patients with definite or probable angina, 50% had restenosis and 19% of patients with restenosis were symptom free.(ABSTRACT TRUNCATED AT 250 WORDS)
A randomized study comparing propranolol and diltiazem in the treatment of unstable angina.
One hundred consecutive patients hospitalized in the coronary care unit for unstable angina, excluding patients with Prinzmetal's variant angina, were randomized within 24 hours of admission to treatment with diltiazem (50 patients) or propranolol (50 patients). Also excluded were patients with previous coronary artery bypass surgery and those receiving a beta-receptor blocking agent at the time of hospital admission. Left ventricular function and the extent of coronary artery disease were similar in the two groups. During the hospital stay, the number of chest pain episodes decreased from a mean (+/- SD) of 0.75 +/- 0.1 per patient per day to 0.26 +/- 0.07 (p less than 0.05) with diltiazem and 0.29 +/- 0.1 (p less than 0.05) with propranolol therapy. The circadian distribution of chest pain episodes was affected similarly. After 1 month, 14 of the patients treated with diltiazem were symptom-free compared with 13 treated with propranolol. At a mean follow-up time of 5.1 months (range 1 to 15), death had occurred in two patients in each group and myocardial infarction in five diltiazem- and four propranolol-treated patients (difference not significant). Coronary artery bypass surgery had been performed in 21 diltiazem- and 19 propranolol-treated patients (difference not significant). Only 15 patients were symptom-free, 9 treated with diltiazem and 6 with propranolol. This similar result observed with the two forms of treatment suggests that coronary artery spasm may not be the main factor involved in unstable angina when Prinzmetal's variant angina is excluded. It also suggests that diltiazem can be used as an alternative to the usual treatment with beta-receptor blocking drugs.
Surgical treatment of the post-infarction left ventricular aneurysm. Factors influencing early and late results.
The early and late results of a 4 year surgical experience with 119 left ventricular aneurysms (LVA) are analyzed. The most common indication for surgery was angina in 78 patients, congestive heart failure (CHF) in 34, arrhythmia in 5 and recurrent embolism in 1. One patient was operated on prophylactically. There were 112 "anterior" and 7 "posterior" aneurysms. Preoperative ventricular function was significantly worse in the CHF group. LVA resection was carried out in 105 patients and a plicature in other 14. In 92 cases the procedure was combined with a myocardial revascularization. Additional cardiac procedures were performed in 14 patients. Overall early (5.9%) and late mortality (18.7%) was significantly higher in the CHF group than in the angina group (14.7% versus 1.3%, p less than 0.01, and 37.9% versus 12.9%, p less than 0.01, respectively). Associated surgical procedures (p less than 0.001) and acuity of the LVA (p less than 0.05) also increased the operative risk. The 5 year-survival was better for the angina group (85.7 +/- 4%) and arrhythmias group (80 +/- 22%) than for CHF patients (46.7 +/- 19%) (p = 0.052). Functional improvement was uniform between survivors of all groups (73.2%). In 15 patients with pre- and postoperative studies hemodynamic parameters were found improved although only a global contractile score did reach significant levels (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
Haemodynamic effects of molsidomine in patients with severe chronic coronary disease.
The haemodynamic effects of a single dose of intravenous molsidomine were assessed in 12 patients with severe coronary disease. The investigation was carried out at rest during angina induced by pacing and after molsidomine during pacing at the rate at which angina had been produced. During angina, left ventricular systolic and end-diastolic pressure rose, left ventricular stroke work fell and coronary flow and myocardial oxygen consumption increased by 58.3% above the control levels. After the administration of molsidomine, atrial stimulation was not followed by angina and there were no significant changes in systolic blood pressure. Left ventricular end-diastolic pressure fell sharply and coronary flow and myocardial oxygen consumption were only 38% and 33% higher, respectively, than the control levels. The beneficial effects of molsidomine in ischaemic heart disease, therefore, are the result of peripheral vasodilation which, by reducing the preload and afterload, lowers the oxygen requirements of the myocardium and thus increase the threshold for angina. A direct action on the coronary network can not be excluded but if such an action does exist it must be very small in the light of the marked systemic effect.
Angiographic findings after myocardial infarction in patients with previous bypass surgery: explanations for smaller infarcts in this group compared with control patients.
The incidence of previous coronary artery bypass surgery (CABS) in patients with acute myocardial infarction admitted to our hospital has risen from 2.3% to 11.2% in 6 years. We compared infarct size and the angiographically determined cause of infarction in 52 control patients and in 52 consecutive patients with acute myocardial infarction at least 2 months after they had undergone CABS. Baseline characteristics were similar in both groups except for a higher incidence of preexisting Q waves in the post-CABS group (22 vs 10; p less than .05). Indexes of myocardial infarct size were smaller in the post-CABS group compared with those in control patients: peak creatine kinease (CK) level (IU/liter) 1113 +/- 1094 (mean +/- SD) vs 1824 +/- 1932 (p less than .01), peak CK-MB level (IU/liter) 173 +/- 230 vs 272 +/- 332 (p less than .02), peak summed ST segment elevation (mm) 3.5 +/- 4.8 vs 8.2 +/- 9.9 (p less than .005), and QRS score on days 7 to 10, 1.9 +/- 3.0 vs 4.3 +/- 3.4 (p less than .001). Postinfarction left ventricular ejection fraction was higher in the post-CABS group (53 +/- 13%) compared with that in control patients (47 +/- 12%; p less than .05). The incidence of total occlusion of the artery to the infarct zone was similar in the post-CABS and control patients (33 vs 27), as was the incidence of one-, two-, and three-vessel disease (artery plus graft). Collateral blood flow to the infarct zone was found in 27 post-CABS patients and in 23 control patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Circadian variation in variant angina.
Thirteen hospitalized patients with variant angina were studied to assess circadian variation in disease activity. Over 48 hours, all angina attacks were noted, a continuous Holter electrocardiogram was recorded and 2 ergonovine tests were performed 12 hours apart, 1 at 4 AM and the other at 4 PM. Only 2 patients gave a clearcut history of more frequent nocturnal or early morning attacks. During the study period, 1.8 +/- 1.6 AM and 0.62 +/- 1.2 PM angina episodes per patient were reported (p less than 0.02), but a circadian pattern was apparent in only 4 patients. However, Holter analysis revealed 5.3 +/- 13.8 AM and 2.6 +/- 8.5 PM episodes of ST elevation per patient (p less than 0.05) and 8.1 +/- 13.9 AM and 3.2 +/- 8.5 PM episodes of ST elevation, ST depression or T-wave pseudonormalization (p less than 0.01). Ten of 11 patients with Holter abnormalities had more frequent AM than PM attacks (p less than 0.01). ST elevation developed during all 13 of the 4-AM and 12 of 13 of the 4-PM ergonovine tests. In 10 cases the ergonovine threshold at which the attack occurred was lower in the morning, in no case was it lower in the afternoon, and in 3 patients the morning and afternoon doses were identical (p less than 0.01). Thus, circadian variation in disease activity both for spontaneous and provoked attacks is present in most patients with variant angina, even though it is often not clinically apparent.
Late tears in leaflets of porcine bioprostheses in adults.
Of 836 patients with a mitral or aortic bioprosthesis who were followed over an 8-year period, 32 required reoperation for prosthetic dysfunction. Of the 26 prostheses removed at operation, 18 (12 mitral and 6 aortic prostheses) showed tears in the valve leaflets. In 7 of the 12 patients with rupture of "mitral" leaflets and in 1 of the 6 patients with torn "aortic" leaflets, the onset of symptoms was sudden, requiring urgent reoperation. Two of the 18 patients died early after reoperation; both had progressive disability and underwent elective operation. In 5 of the 7 patients with torn leaflets in a mitral prosthesis who had acute onset of symptoms, a single tear was found and no gross evidence of calcification was detected. Macroscopic calcification was found in only 8 of the 18 (44.4%) prostheses with torn leaflets (mitral and aortic). Microscopic examination revealed calcific deposits in 9 of the 12 mitral and in all of the aortic bioprostheses. Of the 54 leaflets examined, 29 had tears: 10 were type I; 6, type II; 7, type III; and 6, type IV. Tears in porcine valve leaflets are not an uncommon cause of dysfunction. These tears often lead to acute hemodynamic changes, particularly in the mitral position, and usually require emergency reoperation. They may occur in prostheses that appear grossly normal.
Exercise testing in the early period after myocardial infarction in the evaluation of prognosis.
Prognosis for the patient recovery from an acute myocardial infarction is related mainly to electrical instability, left ventricular function, residual ischemia, and extent of coronary atherosclerosis. Many procedures now exist that allow investigation of these various aspects of cardiovascular function and stratification of risk. No ideal marker of prognosis exists because prognosis is not related to a single factor, because the various determinants are often interdependent, and also because they are time dependent. Thus, the presence of ischemia may be particularly important in the first year when the risk is greater, whereas left ventricular function may be the most important factor thereafter. For this reason, an active strategy for detecting ischemia, by exercise testing or other means, may add to clinical observation. Exercise testing is a safe and noninvasive method that can provide information not only on residual ischemia but also on other aspects of cardiovascular function. Many parameters can be studied, such as ST segment elevation or depression, chest pain, ventricular arrhythmias, tolerance to exercise, completion or not of the test, and the heart rate and blood pressure responses. Some of these data are not specific and must be complemented by further investigation. Such as approach should allow an overall evaluation of the cardiovascular function of the patient and an assessment of risk, and help institute an optimal treatment.
Early and late prognosis after reoperation for prosthetic valve replacement.
From 1969 to 1983, 89 patients underwent replacement of a prosthetic heart valve, an average of 66 months after initial implantation, because of primary failure of the prosthesis in 39 patients (44%), endocarditis in 16 (18%), systemic valve-related complications in 16 (18%), and periprosthetic leaks in 13 (15%). In the remaining five patients (5%), a prosthesis was removed concomitantly with the replacement of another native heart valve. A mechanical valve was replaced in 64 cases (72%) and a bioprosthesis in 25 (28%). Forty-six of the prostheses (52%) were in the mitral position, 37 (42%) were in the aortic position, and six patients (6%) underwent replacement of two prostheses. Preoperatively, four patients were in Functional Class I, 21 in Class II, 37 in Class III, and 27 in Class IV. There were 19 early deaths (21.3%). Early mortality was significantly higher with aortic (35.1%) than with mitral prosthetic valve replacement (8.7%, p less than 0.01). Preoperative diagnosis had a significant correlation with mortality, which was higher with infective endocarditis (62.5%) than with all other indications for operation (12.3%, p less than 0.001). No correlation was found with the preoperative clinical class of the patients. During the time period of this study, there was a marked decline in the mortality rate, which decreased from 29.2% prior to 1979 to 7.4% during the last 2 years (p less than 0.05). Actuarial survival was 60% at 5 years and 38% at 10 years after reoperation. Among the 53 survivors followed up for an average of 39 months, 47 (88.9%) remained in Class I or II and six were in Class III (11.3%) at last follow-up. A second prosthetic valve replacement (third valve replacement) was required in eight patients, three of whom died at re-replacement. Recent improvements in myocardial protection techniques, in the treatment of prosthetic valve endocarditis, and increased surgical experience have contributed to decrease the risk of reoperation for prosthetic valve replacement. Late results are similar to those of a first valve implantation.
Reoperation in patients with patent atherosclerotic coronary vein grafts. A different approach to a different disease.
Atherosclerotic changes are often noted in vein grafts at angiography 8 to 10 years after coronary artery grafting. Reoperation in these patients is hazardous, as manipulation of the grafts may loosen atheromatous debris and cause coronary embolization and myocardial infarction. A technique is described to avoid embolization of atheromatous material during reoperation in patients with patent atherosclerotic coronary vein grafts. This technique was carried out in six patients and compared to the standard technique of reoperation in similar patients. The incidence of complicated perioperative myocardial infarction (0/6 versus 5/12) and perioperative death (zero versus three) was lower when our new technique was used. This approach consists of minimal dissection for access to the right atrium and ascending aorta for cannulation, prompt ligation of all patent grafts at the start of cardiopulmonary bypass, cardioplegic infusion through the ascending aorta and subsequently also through newly inserted grafts using larger infusions until myocardial temperatures reach less than or equal to 15 degrees C, and single aortic clamping for distal and proximal anastomoses.
Subclavian artery to pulmonary circulation fistulas.
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[Postextrasystolic potentiation in aortic insufficiency. Variability of the systemic blood pressure response depending on the ventricular function].
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The value of electrocardiogram and vectorcardiogram in diagnosis of left atrial enlargement.
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Experimental and clinical study of right peripheric block in the subpulmonar anterior zone.
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European concern over BSE transmission.
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