[Clinical relevance of equilibrium radionuclide ventriculography].
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Coronary Artery Bypass↗
Biomedical subjects
H Klepzig
Publications and source records attributed to H Klepzig.
Coronary artery stenosis and occlusion: value of 99Tcm-MIBI SPECT.
The aim of this study was to evaluate and validate a new quantification method for 99Tcm-sestamibi single photon emission computed tomographic (SPECT) myocardial imaging based on a four-slice analysis method and to check the functional results of percutaneous transluminal coronary angioplasty (PTCA). Using the calculated pathological area of the scintigram as an index for myocardial ischaemia, the overall sensitivity was 81-90% and the overall specificity was 74-98%. Analysis of variance of the repeated measurements revealed good reproducibility (coefficient of variation 8.4%). A significant correlation was found between the size of the exercise-induced perfusion defects and the degree of coronary stenosis. The comparison of radionuclide ventriculography and the perfusion image in 27 patients revealed a good correlation between the resting global ejection fraction and myocardial perfusion, but there was no correlation during exercise, indicating a dissociation between myocardial perfusion and function during exercise conditions in patients with coronary artery disease (CAD). Patients with total coronary occlusions showed more resting defects than patients with partial stenoses. Both groups benefit from PTCA or re-opening of chronic coronary occlusion, respectively. Exercise-induced myocardial ischaemia significantly decreased, and in 36% of the patients with previous myocardial infarction a significant reduction of the size of the resting perfusion defects occurred. In conclusion, our quantification method is suitable for the accurate non-invasive diagnosis of CAD, and for the follow-up of the invasive treatment of coronary artery stenoses and occlusions.
Adult↗
[Imaging methods in cardiology. Coronary heart disease].
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Coronary Disease↗
[Angiography follow-up after transluminal angioplasty of coronary bypass grafts].
Between January 1979 and October 1991, percutaneous transluminal angioplasty of stenosed or occluded coronary bypass grafts was attempted 180 times in 146 patients (180 lesions in 157 bypass grafts); 6/157 grafts were internal mammary grafts. The procedure was successful in 129/157 grafts (82%) and in 151/180 lesions (84%). Failures occurred almost exclusively in recanalization attempts. Cardiac complications occurred in 4/146 patients (2.7%). Three patients developed an acute myocardial infarction, another patient died after acute occlusion of a native vessel dilated during the same procedure. In successful attempts the severity of stenosis was reduced from 87 +/- 10% to 33 +/- 15%. 113/129 successfully dilated grafts had at least one (mean 2.7) control angiogram. 54/113 (48%) showed recurrence after a mean follow up of 6 months. An additional 15 grafts showed late restenosis in a second control angiogram (mean follow-up 23 months). The total restenosis rate was 61%. Restenoses were dilated again one to six times (mean 1.9) with comparable success and recurrence rate. Two patients died during the sixth angioplasty. Finally, 32/129 (25%) grafts were occluded or presumably occluded, and 97/129 (75%) were angiographically confirmed open without restenosis. Thus, angioplasty of bypass grafts is an alternative to a repeat revascularization surgery. The acute results are comparable to the results of angioplasty in native coronary arteries. The restenosis rate is high. One has to be aware of late restenosis. Restenosis can be dilated repeatedly with a comparable success rate and with no significant increase in restenosis rate.
Adult↗
[Sympathetic reinnervation following heart transplantation--a double-tracer study with 123I-MIBG and 201Tl].
Sympathetic reinnervation was evaluated in 15 patients 2-69 months after heart transplantation using a double-tracer technique with 123I-MIBG and 201Tl. Since MIBG is accumulated in the same manner as norepinephrine it may serve as a tracer of the integrity and function of the sympathetic nervous system. 201Tl was used for landmarking. Planar anterior imaging was performed 15 min and 4 h after i.v. injection of 220 MBq 123I-MIBG and 37 MBq 201Tl. Image quantitation was based on the ratio of myocardial to mediastinal MIBG-uptake. Cardiac regions of interest were defined according to the 201Tl uptake. There was no evidence of sympathetic reinnervation in 8 patients 2-34 months after transplantation. Increased MIBG-uptake could be observed in the anterior basal region in 6 long-term cardiac transplants (37-69 months). One patient with a 59-month-old transplanted heart did not reinnervate. Increased MIBG-uptake in the anterior basal region indicating partial sympathetic reinnervation could be shown in 40% of the investigated patients with an average organ age of 51 months.
3-Iodobenzylguanidine↗
[Therapy of acute myocardial infarct with thrombolytic drugs. Can use of thrombolytic therapy be further improved?].
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Angioplasty, Balloon, Coronary↗
SIN-1 has no direct myocardial anti-ischemic action.
Anti-ischemic drugs may develop their cardiac activity via peripheral (reduction in preload and/or afterload) or cardiac (coronary vasculature, myocardial cell metabolism) effects. The aim of the study was to investigate whether SIN-1, the active metabolite of molsidomine, develops a direct myocardial anti-ischemic property. Three groups of seven patients each were treated with 0.4 mg SIN-1 administered via either the intracoronary (IC) or intravenous (IV) route, or with placebo in a double-blind randomized investigation. SIN-1 had no influence on either the ischemic parameters in the surface electrocardiogram (ECG) or the intracoronary ECG. There was also no change in peripheral or central hemodynamics or in the severity of angina following this low IC or IV dosage. There is no evidence of a direct myocardial anti-ischemic response of SIN-1. The well known anti-ischemic activity of SIN-1 or molsidomine has to be attributed to the proven peripheral and cardiac vascular responses.
Angioplasty, Balloon, Coronary↗
Noradrenaline depletion in patients with coronary artery disease before and after percutaneous transluminal coronary angioplasty with iodine-123 metaiodobenzylguanidine and single-photon emission tomography.
Iodine-123 metaiodobenzylguanidine (MIBG) is a noradrenaline analogue which can be used as a tracer to investigate the cardiac sympathetic nervous system. Regional ischaemia leads to noradrenaline depletion with functional denervation which can be demonstrated by reduced MIBG uptake. In order to evaluate the reversibility of ischaemia-associated damage to the sympathetic nervous system, neuronal scintigraphy with 123I-MIBG and myocardial rest and stress perfusion scintigraphy with technetium-99m sestamibi was performed in 16 patients with coronary artery disease before and 3-4 months after percutaneous transluminal coronary angioplasty (PTCA). Partial re-innervation occurred in five patients, the degree of stenosis of remaining lesions being estimated by repeat angiography to be below 40%. Unchanged MIBG defects could be confirmed in four patients with residual lesions of between 40% and 50%. Increased MIBG defects were shown in three patients with significant restenoses of more than 70%. In all patients the neuronal defects exceeded the ischaemia-induced or scar-associated perfusion defects. Three patients dropped out of this study: one for technical reasons, one due to emergency aortocoronary bypass surgery and one due to diabetic polyneuropathy. This investigation shows that the sympathetic nervous system is highly sensitive to ischaemia. Further studies need to be done to assess the conditions allowing re-innervation after PTCA.
3-Iodobenzylguanidine↗
Accuracy of blood sampling through central venous lines in intensive-care unit patients.
OBJECTIVE: In intensive-care unit (ICU) patients it is common practice to sample blood from central venous lines (CVL). This study was designed to answer the question on how much blood has to be aspirated through the CVL before the actual blood sample is taken to get accurate laboratory findings. DESIGN AND SETTING: Simultaneous blood samples from a peripheral vein (intraindividual control) and 5-ml portions from a CVL up to 25 ml were analyzed. PATIENTS: 5 patients of an internal ICU participated in the study. RESULTS: For the analyzed 24 different parameters it could be shown that after aspirating 10 ml of blood, the results are comparable to analyses from peripheral vein samples. CONCLUSIONS: Although blood sampling from a CVL--after aspiration of 10 ml blood--results in correct laboratory analyses, this procedure leads to a greater amount of blood loss and, hence, cannot be recommended in long-term ICU treatment.
Aged↗
[Improvement in myocardial function and perfusion after recanalizing a chronic coronary artery occlusion].
The purpose of the study was to evaluate the improvement of the left ventricular ejection fraction and myocardial perfusion after recanalization of chronic coronary artery occlusions. The patients were investigated by rest and exercise radionuclide ventriculography (25/31) and rest and exercise myocardial scintigraphy (22/31). The examinations were performed 3 +/- 1 days before and within 7 days and 4 months after recanalization. Exercise-induced chest pain was present in 77% (24/31) of the patients before, in 10% (3/31) after recanalization and in 23% (7/31) during follow-up. Six of the 7 patients with exercise-induced chest pain after 4 months developed restenosis in the former reopened coronary artery. The results of the exercise-ECG present that 71% (22/31) of the patients had ST-segment-depression before, 19% (6/31) after catheter-intervention and 26% (8/31) during follow-up. Six of the 8 patients with exercise-induced ST-depression after 4 months had a restenosis in the former reopened coronary artery. Reopening resulted in an increase of global rest ejection fraction (EF) from 51 +/- 11% to 54 +/- 13% (p < 0.05) and sectorial EF from 56 +/- 17% to 61 +/- 21% (p < 0.01) after recanalization. After 4 months patients with excellent angiographic results still had an increased global and sectorial EF at rest (global: 54 +/- 9%, sectorial: 59 +/- 17%; n.s.). Patients with restenosis (note: no reocclusion) developed a decrease of global and sectorial rest EF (global: 49 +/- 14%, sectorial: 57 +/- 19%; n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)
Angina Pectoris↗
[Improved left ventricular ejection fraction directly after transluminal coronary angioplasty].
The purpose of this study was to evaluate if left ventricular ejection fraction (EF) at rest can improve already during the first 4 h after successful transluminal coronary angioplasty (PTCA). Measurements were carried out with the CardioScint LV Function Monitor Version 1.3. Comparison of ejection fraction values evaluated by the CardioScint Monitor revealed a good correlation with usual equilibrium radionuclide ventriculography (n = 28; r = 0.89). Also, intra- and interobserver variability was low (n = 26; r = 0.94 and n = 21; r = 0.92 respectively). Two hundred follow-up-measurements in eight patients over a time period of 4 h revealed a significant decrease of EF from 45 +/- 12% to 39 +/- 18% (p = 0.037) (reference group). This decrease was due to a continuous increase of background activity. The study population consisted of 14 patients with successful PTCA (dilatation from 85 +/- 7 to 34 +/- 9% linear vessel diameter). To evaluate the hemodynamic significance of the coronary lesion, left ventricular ejection fraction was registered during the balloon occlusion of the vessel. After dilatation, 25 EF measurements were carried out in each patient over the following 4 h (350 values). During PTCA, EF decreased from 52 +/- 16 to 37 +/- 9% (p = 0.0027). During the 4-h follow-up EF slightly decreased from 50 +/- 8 to 46 +/- 9% (p = 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Left ventricular function during symptomatic and asymptomatic myocardial ischemia].
Transluminal coronary angioplasty (PTCA) causes transient occlusion of the coronary artery and temporary ischemia of the left ventricle. Left ventricular dysfunction during silent and symptomatic episodes of myocardial ischemia during PTCA was evaluated continuously with a newly developed miniature, non-imaging scintillation probe. Parameters of left ventricular function were compared before and during balloon inflations of 60 s duration: ejection fraction (EF), indices of end-systolic and end-diastolic volumes (ESV, EDV), peak ejection and peak filling rates (PER, PFR). 13 patients (age 54 +/- 7.4 years) were symptomatic, 10 patients (age 61 +/- 8 years) were asymptomatic. Impairment of left ventricular function during ischemia did not show any significant differences between the symptomatic and asymptomatic patients. It is therefore concluded that symptomatic and asymptomatic episodes of myocardial ischemia during PTCA cause similar impairment of systolic and diastolic left ventricular function. The degree of left ventricular dysfunction during PTCA cannot be estimated on the basis of clinical symptoms.
Aged↗
Changing patterns of patients undergoing emergency surgical revascularization for acute coronary occlusion. Importance of myocardial protection techniques.
Between 1977 and 1992 a total of 163 consecutive patients underwent emergency coronary artery bypass grafting after acute coronary occlusion (94% after failed angioplasty). Patients were divided into four groups according to the method used for myocardial protection. The crystalloid cardioplegia group included 30 patients operated on from 1977 to 1980; the hypothermic fibrillation group included 60 patients (1980 to 1986); the blood cardioplegia group included 36 patients (1986 to 1989); and the blood cardioplegia with controlled reperfusion group included 37 patients (1989 to 1992). Preoperative data, ischemic time interval, collateral blood flow, intraoperative data, regional wall motion, global ejection fraction, myocardial infarct-specific electrocardiographic changes, enzyme release, rhythm disturbances, mortality, prevalence of intraaortic balloon pumping, and inotropic support were assessed in this retrospective study. Our data indicate that the current spectrum of patients undergoing emergency coronary artery bypass grafting after acute coronary occlusion are at a significantly higher risk compared with those 15 years ago, that is, increase in age (53 +/- 1 versus 59 +/- 2 years; p < 0.05), three-vessel disease (38% versus 3%; p = 0.004), acute occlusion of the left main coronary artery (11% versus 0%; p = 0.02), preoperative cardiogenic shock (35% versus 3%; p = 0.007), prevalence of acute two-vessel occlusion (22% versus 3%; p = 0.05), prevalence of previous infarction (59% versus 23%; p = 0.04), and duration of ischemia (3.0 +/- 0.2 versus 4.1 +/- 0.3 hours; p < 0.05). Despite the increase in patients with severely compromised ventricular function during recent years, the overall hospital mortality decreased to 5% (2/37) when maximal protection of the ischemic and remote myocardium was performed (preoperative intraaortic balloon pump, combined antegrade/retrograde substrate-enriched blood cardioplegia, warm induction, controlled reperfusion, prolonged vented bypass). Single-vessel disease was always associated with a low mortality, whereas mortality could be reduced with controlled blood cardioplegia in patients with multivessel disease (6%) and cardiogenic shock (15%). The immediate return of regional contractility in the previously ischemic area after controlled reperfusion might serve as an explanation for these favorable results. After unmodified blood reperfusion, normokinesis or slight hypokinesis occurs in only 34% to 46% in the early postoperative period (1 to 4 weeks) in comparison with 86% after controlled blood cardioplegia reperfusion (p < 0.05). We conclude that there is a significant increase in risk factors in patients undergoing emergency coronary artery bypass grafting and that improved methods of intraoperative myocardial protection are needed for these compromised patients.
Acute Disease↗
[Does ST-elevation in stress ECG depend on the extent of collateral circulation?].
As a possible cause of exercise-induced ST-elevation in patients without myocardial infarction, a poor or absent coronary circulation to the poststenotic coronary segment was postulated. To check this thesis, we examined 10 patients (pts.) with ST-elevation, respectively, ST-depression and comparable coronary status (coronary score 12 vs. 12; mean stenosis diameter 86 vs. 85%) and exercise parameters (work load 150 vs. 137.5 Watts; exercise duration 2.8 vs 3.5 min) with regard to their collateral circulation. In the group with ST-elevation there were nine pts. with severe proximal stenosis of the left anterior descending artery (LAD) and one pt. with a stenosis in the middle third of the right coronary artery. The 10 patients with ST-depression had a proximal stenosis in the LAD. The extent of the angiographically seen collaterals was equal in both groups. As a result, this study demonstrates that the size of the collateral circulation has no influence on the exercise-induced ST-elevation. The most plausible cause of exercise-induced ST-elevation is a functional decrease of the lumen of a severe stenosis.
Arrhythmias, Cardiac↗
[Lowering increased cholesterol--prolonging life?].
Epidemiologic surveys reveal a positive correlation between serum cholesterol levels and the incidence of coronary artery disease. Intervention trials demonstrated that a reduction of serum cholesterol by 1% results in a decrease of coronary non-fatal events by 2%. Fatal coronary events remain almost uninfluenced. On the other side, several intervention trials showed an excess mortality from non-cardiac causes in the therapy groups (i.e. malignant tumors, suicides, accidents). Thus, until now no prolongation of life expectancy could be verified by cholesterol lowering measures.
Cause of Death↗
[Iatrogenic origin of pleural effusion. A rare complication of the central venous catheter].
CASE REPORT: A 47-year-old woman with unremarkable plain chest X-rays in whom the Seldinger technique was employed to place a central venous line via the jugular vein, a catheter-related pleural effusion developed. CONCLUSIONS: This case points up the need to exercise care when placing a central venous line, and suggests the need to use contrast medium for the radiological follow-up examination.
Acute Disease↗
[Captopril in acute myocardial infarct: its effect on infarct size and arrhythmias].
The effect of captopril on infarct size and arrhythmias was determined in a prospective, randomized, placebo-controlled double-blind study of 46 patients (9 women, 37 men; mean age 61 [38-86] years). Within 2-18 hours of entry into the study these patients received either a slow intravenous bolus injection of 2.5 or 5.0 mg captopril followed by a continuous infusion of 1.5-2.0 mg/h for a period of 48 hours (n = 22), or of a placebo by the same mode of administration (n = 24). The two groups were comparable as to age, infarct site and time of intervention. All patients, except one in each group, also received nitroglycerin (1.2-6.0 mg/h intravenously). QRS complexes were measured to provide a necrosis index. Q-wave amplitudes decreased under captopril (-0.08 +/- 0.04 mV) while increasing under placebo (+0.15 +/- 0.04 mV; P less than 0.05). The number of ventricular extrasystoles in the first 24 hours after onset of treatment or on placebo was 25/h and 9/h, respectively (P less than 0.02). Ventricular fibrillation occurred in 7 patients of the placebo group, in none of the captopril group. Creatine-kinase infarct weight was 59 and 45 gram-equivalents, respectively (placebo vs treated group: not significant). The mean arterial blood pressure fell by 14 mm Hg during the first hour in the captopril group, but by only 3 mm Hg on placebo (P less than 0.01). These results indicate that captopril has a favourable influence on infarct size and electrical stability which is additional to that provided by standard nitroglycerin treatment.
Adult↗
Effect of propranolol and disopyramide on left ventricular function at rest and during exercise in hypertrophic cardiomyopathy.
In 19 patients with hypertrophic cardiomyopathy (15 males, 4 females, mean age 49.2 +/- 10.8 years) left ventricular function was studied with radionuclide ventriculography at rest and during exercise in a crossover design without intervention and after disopyramide and propranolol treatment. 15 of the 19 patients had a resting or latent intraventricular gradient of more than 30 mm Hg. Left ventricular function at rest and during exercise was evaluated before medication, 90 min after oral administration of 200 mg disopyramide or 160 mg propranolol and after 3 weeks of oral therapy with disopyramide 200 mg 2 times a day or propranolol 80 mg 4 times a day. After long-term treatment with disopyramide, resting ejection fraction decreased from 72 +/- 12 to 69 +/- 14% (p less than 0.01) and peak ejection rate (PER) decreased from 3.46 +/- 135 to 3.24 +/- 65 end-diastolic volume (EDV).s-1 (p less than 0.01). Peak filling rate (PFR) at rest decreased from 3.01 +/- 0.8 to 2.77 +/- 0.63 EDV.s-1 (p less than 0.05). Time to peak filling rate (TPFR) at rest and during exercise after acute and chronic therapy did not change compared to control values. Acute and long-term administration of propranolol lead to a significant reduction in heart rate at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
Administration, Oral↗