Early vectorcardiographic monitoring provides prognostic information in patients with ST-elevation myocardial infarction

OBJECTIVE: To evaluate the prognostic value of specified vectorcardiographic data obtained during the first hours of ST-elevation myocardial infarction for cardiac outcomes up to 5 years. DESIGN: Three hundred and five patients with ST-elevation myocardial infarction and chest pain for less than 12 h were monitored with continuous vectorcardiography. RESULTS: All patients had follow-up for at least 1 year. The mortality was 5.9% at 30 days and 10.8% at 1 year. The estimated 5-year mortality was 24%. A total of 7.9% had recurrent infarction at 30 days and 11.2% at 1 year. Recurrent infarction or death occurred in 12.1% at 30 days and in 19.7% at 1 year. The presence of ST-VM (plateau) >or= 125 microV was highly predictive of the combined endpoint death or recurrent infarction at 1 year, OR 2.69 (95% CI 1.39-5.23). Multivariate analysis showed that age >or=75 years, anterior myocardial infarction, and the presence of ST-VM (plateau) >or= 125 microV, were independently associated with increased risk of recurrent infarction or death at 1 year and with death at 5-year follow-up. A start value of ST-VM 相似文献   

Early vectorcardiographic monitoring provides prognostic information in patients with ST-elevation myocardial infarction

Objective--To evaluate the prognostic value of specified vectorcardiographic data obtained during the first hours of ST-elevation myocardial infarction for cardiac outcomes up to 5 years. Design--Three hundred and five patients with ST-elevation myocardial infarction and chest pain for less than 12?h were monitored with continuous vectorcardiography. Results--All patients had follow-up for at least 1 year. The mortality was 5.9% at 30 days and 10.8% at 1 year. The estimated 5-year mortality was 24%. A total of 7.9% had recurrent infarction at 30 days and 11.2% at 1 year. Recurrent infarction or death occurred in 12.1% at 30 days and in 19.7% at 1 year. The presence of ST-VM[Formula: See Text]?≥?125?μV was highly predictive of the combined endpoint death or recurrent infarction at 1 year, OR 2.69 (95% CI 1.39-5.23). Multivariate analysis showed that age ≥75 years, anterior myocardial infarction, and the presence of ST-VM[Formula: See Text]?≥?125?μV, were independently associated with increased risk of recurrent infarction or death at 1 year and with death at 5-year follow-up. A start value of ST-VM ≤?100?μV identified a group of patients with low risk of death or re-infarction within 1 year. Conclusion--Continuous vectorcardiography during the first hours after thrombolytic treatment of patients with ST-elevation myocardial infarction provides important prognostic information. A new vectorcardiographic variable, ST-VM[Formula: See Text], identifies a group of patients with increased risk of recurrent infarction or death. As well, patients with low risk of recurrent infarction or death were identified by low start values of ST-VM.     

Assessment of myocardium at risk with computerized vectorcardiography and technetium-99m-sestamibi-single photon emission computed tomography during coronary angioplasty

OBJECTIVE: To compare the myocardium at risk (MAR) as estimated by computerized vectorcardiography (cVCG) with MAR determined by Tc-99m-sestamibi-SPECT using coronary angioplasty as the model for transient transmural ischemia in humans. METHODS AND RESULTS: In 37 patients with stable angina pectoris, cVCG was recorded continuously during coronary angioplasty. The scintigraphic defect was quantified using an automated software program (CEqual). The ST vector magnitude (ST-VM) and the ST change vector magnitude (STC-VM) correlated well with MAR estimated by scintigraphy, ST-VM (r = 0.71, p < 0.001) and STC-VM (r = 0.84, p < 0.001). All patients with STC-VM <50 microV during occlusion had defects of less than 10% of the left ventricle. CONCLUSION: 1) ST-VM and STC-VM give a reasonable useful estimate of MAR size during transient coronary occlusion. 2) STC-VM <50 microV is a reliable limit to identify patients with MAR size less than 10%. 3) ST-VM does not add information to STC-VM with respect to detection of ischemia. 4) The existence of collateral vessels has great impact on both ST-vector changes and scintigraphic imaging of myocardial ischemia.     

Assessment of Myocardium at Risk with Computerized Vectorcardiography and Technetium-99m-Sestamibi-Single Photon Emission Computed Tomography during Coronary Angioplasty

Objective - To compare the myocardium at risk (MAR) as estimated by computerized vectorcardiography (cVCG) with MAR determined by Tc-99m-sestamibi-SPECT using coronary angioplasty as the model for transient transmural ischemia in humans. Methods and results - In 37 patients with stable angina pectoris, cVCG was recorded continuously during coronary angioplasty. The scintigraphic defect was quantified using an automated software program (CEqual). The ST vector magnitude (ST-VM) and the ST change vector magnitude (STC-VM) correlated well with MAR estimated by scintigraphy, ST-VM ( r = 0.71, p < 0.001) and STC-VM ( r = 0.84, p < 0.001). All patients with STC-VM <50 &#119 V during occlusion had defects of less than 10% of the left ventricle. Conclusion - 1) ST-VM and STC-VM give a reasonable useful estimate of MAR size during transient coronary occlusion. 2) STC-VM <50 &#119 V is a reliable limit to identify patients with MAR size less than 10%. 3) ST-VM does not add information to STC-VM with respect to detection of ischemia. 4) The existence of collateral vessels has great impact on both ST-vector changes and scintigraphic imaging of myocardial ischemia.     

Preoperative and postoperative technetium-99m pyrophosphate myocardial scintigraphy in the assessment of operative infarction in coronary artery surgery.

The incidence of operative myocardial infarction was assessed by electrocardiogram (ECG) and technetium-99m pyrophosphate (99mTc-PyP) myocardial scintigrams in 89 consecutive patients undergoing coronary artery bypass grafting (CABG). Myocardial scintigrams were performed on the day before operation and repeated 2 to 3 days postoperatively. All patients survived operation, with three in-hospital deaths not related to myocardial infarction (mortality rate 3 percent). Operative infarction was assessed to have occurred in four of 89 patients (4 percent). Two had new Q waves and positive scintigrams; one, major ST-T wave changes and a positive scintigram; and the fourth, new Q waves without a positive scintigram. Three further patients (3 percent) had Q waves and positive scintigrams postoperatively, but myocardial infarction was evolving before anesthesia and operation. Twenty-seven of 89 patients (30 percent) were found to have abnormal scintigrams preoperatively. In two patients, both operated upon with evolving myocardial infarction, the scintigram was worse postoperatively. In 13 patients the scintigram was improved after operation. In 12 patients (13 percent) the abnormal preoperative scintigram was unchanged after operation. Preoperative and postoperative myocardial scintigrams and ECG's must be compared to assess the incidence of operative myocardial infarction in patients undergoing CABG.     

Cardiac arrhythmias and myocardial ischemia after thoracotomy for lung cancer.

The records of 598 patients undergoing a thoracic surgical procedure for lung cancer from 1975 through 1989 were reviewed for occurrence of cardiac arrhythmias and myocardial ischemic events. Atrial tachycardias occurred in 16% (94/598); atrial fibrillation was preponderant (87%), followed by supraventricular tachycardia and atrial flutter. Patients with recurrent episodes of dysrhythmias had a significantly higher mortality rate than those without episodes or with a single episode only (17% versus 2.4%; p less than 0.01). Transient ischemic electrocardiographic changes were documented in 23 patients (3.8%) and myocardial infarction in 7 (1.2%). An abnormal preoperative exercise test result and intraoperative hypotension were strongly associated with both dysrhythmia and ischemia (p less than 0.01). Pneumonectomy, ischemic changes on the electrocardiogram, and cardiac enlargement were also associated with arrhythmias (p less than 0.01). A weaker association (p less than 0.05) was found between postoperative arrhythmias and old myocardial infarction (greater than 6 months), arterial hypertension, and heart failure. Pulmonary function had no predictive value in this respect. A history of angina or old myocardial infarction was predictive of transient postoperative myocardial ischemia but not myocardial infarction. Despite improved anesthetic and monitoring techniques and more frequent use of the intensive care unit postoperatively in the last decade, the incidence of arrhythmias after thoracotomy has not decreased. More effective prevention is needed, particularly for patients with defined preoperative and perioperative risk factors.     

Fatal myocardial infarction following carotid endarterectomy: three hundred thirty-five patients followed 6-11 years after operation.

Routine coronary angiography has been recommended to all patients undergoing carotid endarterectomy at the Cleveland Clinic since 1978. Patients found to have severe, correctable coronary artery disease (CAD) have been advised to undergo myocardial revascularization as a staged or combined procedure in conjunction with carotid endarterectomy in an attempt to reduce the incidence of fatal myocardial infarction during the postoperative period, and during the late follow-up interval. In order to provide an historic standard with which the results of this approach may eventually be compared, complete follow-up information has been obtained for 95% of 335 consecutive patients who underwent carotid endarterectomy between 1969 and 1973. Fatal myocardial infarction accounted for 60% of early deaths within 30 days of operation and occurred in 1.8% of the entire series. Among the patients who survived operation, the five-year mortality rate was 27%, and the 11-year mortality rate was 48%. Myocardial infarction caused 37% of the deaths that occurred within five years after operation and 38% of the deaths that have occurred within 11 years. Differences in the incidence of fatal myocardial infarction within five years after operation between a group of 116 patients who had no clinical evidence of CAD and a group of 209 patients suspected to have CAD attained statistical significance (p less than 0.1) despite the fact that 67 patients suspected to have CAD eventually underwent myocardial revascularization. Improvement in actuarial survival (p less than 0.05) and reduction in the late mortality rate (p less than 0.01) were statistically significant for the subset of patients with suspected CAD who had aortocoronary bypass graft procedures.     

Does the clinical evaluation of the cardiac status predict outcome in patients with abdominal aortic aneurysms?

A cost-effective method to reduce mortality rates after abdominal aortic aneurysm repair centers on selecting and investigating only those patients at risk for cardiac-related death. All 146 patients undergoing asymptomatic abdominal aortic aneurysm repair over a 5-year period (1986 to 1990) were retrospectively placed into one of the three following groups on the basis of a clinical evaluation. Group I: no history of myocardial infarction or angina, no congestive heart failure, and no ischemic changes on electrocardiogram (ECG). Group II: history of myocardial infarction or class I-II angina or ischemic changes on ECG. Group III: presence of congestive heart failure or class III-IV angina. Patients in group I had no further cardiac work-up; patients in group II with angina had left ventricular ejection fraction assessment by multiple gated acquisition (all greater than 37%) and were cleared for operation by a cardiologist; patients in group II without angina had no further cardiac work-up; patients in group III had coronary angiography and then coronary revascularization. The overall mortality rate was 4.8%, with a cardiac mortality rate of 3.4%. The mortality rate in group I (n = 64) was 1.8%, with no cardiac-related deaths; the mortality rate in group II (n = 63) was 9.5% (8% cardiac-related deaths). No deaths occurred in group III (n = 19). The difference between the cardiac mortality rates in groups I and II was significant (p = 0.02) as was the postoperative cardiac morbidity: total myocardial infarctions (p less than 0.001); congestive heart failure (p = 0.02); tachyarrhythmias (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Fatal myocardial infarction following lower extremity revascularization. Two hundred seventy-three patients followed six to eleven postoperative years.

Routine preoperative coronary angiography has been recommended to all patients scheduled for elective lower extremity revascularization at the Cleveland Clinic since 1978. Patients found to have severe, correctable coronary artery disease (CAD) have been advised to undergo myocardial revascularization prior to surgical management of lower extremity ischemia in an attempt to reduce the incidence of fatal postoperative myocardial infarction. In order to provide an historic standard with which the results of this approach may eventually be compared, complete follow-up information has been obtained for 95% of 273 consecutive patients who underwent lower extremity revascularization between 1969 and 1973. Fatal myocardial infarction accounted for 52% of early postoperative deaths and occurred in 3.3% of the entire series. Among the patients who survived operation, the five-year mortality rate was 20% and the 11-year mortality rate was 40%. Complications of CAD caused 50% of the deaths that occurred within five years postoperatively and 55% of the deaths that have occurred within 11 years. The incidence of fatal myocardial infarction within five years after operation among patients who had preoperatively evidence of CAD was statistically significant (p less than 0.01).     

Coronary artery bypass grafting within thirty days of acute myocardial infarction. Early and late results in 406 patients

Between 1981 and 1987, 1726 coronary artery bypass operations were performed by a single group of surgeons at a community hospital. Overall hospital mortality in this group was 2.4% (41/1726). Of these patients 406 were operated on within 30 days of an acute myocardial infarction. The hospital mortality rate in this group was 6.7% (27/406) versus 1.1% (14/1320) in patients operated on without evidence of recent acute myocardial infarction (p less than 0.0001). In these 406 patients, sex, location of acute myocardial infarction, type of infarction, coronary anatomy, presence of postinfarction angina, technique of myocardial preservation, and the time from infarction to operation were not associated with hospital mortality. Univariate and multivariate analyses showed that three factors were significantly associated with increased hospital death: poor ejection fraction, less than 30% (p less than 0.0001), preoperative shock (p = 0.0005), and age greater than 70 years (p = 0.004). Follow-up was 90% complete (365/406 patients) at a mean time of 35 +/- 21 months. Of these patients 80% (292/365) were in New York Heart Association functional class I, and 10% (36/365) were in functional class II. Of all patients 88% were alive at 3 years, and 84% were alive at 5 years after operation. Multivariate comparison of survival curves showed that ejection fraction less than 30% was associated with decreased survival (p = 0.0002), followed by age (p = 0.0009). Patients younger than 70 years with an ejection fraction greater than 30% and not in cardiogenic shock can be operated on at any time after acute myocardial infarction without increased risk. Long-term survival and freedom from symptoms can be expected in these patients.     

Coronary bypass surgery early after thrombolytic therapy for acute myocardial infarction

The safety of coronary bypass operations after coronary reperfusion with streptokinase for acute myocardial infarction is not well documented. Therefore we studied 23 consecutive patients (mean age, 59.5 years; 22 men) undergoing bypass operations a median of 5 days (range, 1 to 23 days) after thrombolysis (streptokinase). The control group consisted of 169 concurrent patients of similar mean age (58.8 years) having bypass operations for standard indications. The preoperative angiographic ejection fraction was 68 +/- 14% in the control patients and 61 +/- 14% in the streptokinase group (p less than 0.05). The number of diseased vessels (70% stenosis or greater) averaged 2.6 in control and 2.3 in streptokinase patients. A previous myocardial infarction had occurred in 42% of the controls and all of the streptokinase patients. Aortic cross-clamp times did not differ between the two groups (80 +/- 35 minutes for the controls and 68 +/- 25 minutes for the streptokinase group). Cardiopulmonary bypass times were similar: 108 +/- 45 minutes in the controls versus 109 +/- 28 minutes in the streptokinase group. Grafts per patient averaged 3.7 +/- 1.5 for the controls versus 2.8 +/- 1.1 for the streptokinase patients (p less than 0.01). Difficult operative hemostasis was noted in 4% of both groups. Inotropic support was given postoperatively to 11% of the control and 13% of the streptokinase patients (p = not significant). Measured blood loss during the first 48 hours postoperatively was similar, averaging 809 ml in controls and 776 ml in the streptokinase group. Blood product replacement was also comparable: mean, 713 ml in the control group versus 759 ml in the streptokinase group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vectorcardiographic changes during laparoscopic cholecystectomy may mimic signs of myocardial ischaemia

Background: Laparoscopic surgery involves the use of intra-ab-dominal carbon dioxide insufflation (pneumoperitoneum). The increased intra-abdominal pressure causes marked haemodyn-amic changes, which may influence electrocardiographic monitoring. The aim of the present study was to elucidate the influence of pneumoperitoneum on vectorcardiographic recordings.
Methods: Vectorcardiographic changes (QRS vector difference= QRSVD, QRS loop area, QRS magnitude, ST vector magnitude, spatial ST vector change) were recorded continuously applying computerized vectorcardiography in 12 anaesthetised cardio-vascularly healthy patients, scheduled for laparoscopic cholecystectomy.
Measurements were made before and during pneumoperitoneum in three different body positions (supine, Trendelenburg and reversed Trendelenburg), also employing transesophageal echo-cardiography and invasive blood pressure monitoring. Results: Pneumoperitoneum significantly increased QRSVD, in parallel with an enlargement in loop area and magnitude. The magnitude was significantly increased in the transversal and frontal planes and there was a tendency to increase the magnitude in the sagittal plane. The increase in QRS-VD reached levels previously associated with the development of myocardial ischaemia in patients with coronary artery disease. The ST-variables were not changed by the pneumoperitoneum. The positional changes also influenced QRSVD significantly.
Conclusions: When computerized vectorcardiography is used for ischaemia monitoring during pneumoperitoneum, the ST-variables seem reliable. However, vectorcardiographic QRS changes should be interpreted with caution, as the QRS alterations found during pneumoperitoneum mimic the changes seen during myocardial ischaemia.     

Silent myocardial ischemia monitoring predicts late as well as perioperative cardiac events in patients undergoing vascular surgery.

In a previous study we have shown that perioperative monitoring for silent myocardial ischemia can noninvasively identify those patients undergoing peripheral vascular surgery who are at significantly increased risk for perioperative myocardial infarction. In the present study a group of 385 patients undergoing peripheral vascular surgery was studied long-term as well as short-term to determine whether perioperative monitoring for silent ischemia can identify those patients who are at significantly increased risk of late cardiac death or late cardiac complications as well as those patients at increased risk of perioperative myocardial infarction. All patients were monitored before, during, and after operation and were divided into two groups on the basis of results of monitoring: patients whose total duration of silent ischemia as a percentage of the total duration of perioperative monitoring was 1% or greater (group I, n = 120) and those for whom this value was less than 1% (group II, n = 265). Among patients in group I 13.3% (16 of 120) suffered a perioperative myocardial infarction in contrast to only 1.1% (3 of 265) patients in group II (p less than 0.001). Multivariate logistic regression analysis of preoperative and perioperative characteristics showed that the presence of a total perioperative percent time ischemic 1% or greater and age were the only significant predictors of perioperative myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiocirculatory disturbances after surgery of carcinoma of the thoracic esophagus

From 1976 to 1985, 277 cases of carcinoma of the esophagus were resected in the Second Department of Surgery, Tohoku University School of Medicine. Postoperative cardiocirculatory disturbances occurred in 114 cases (41.2%), arrhythmia being the disturbance most frequently observed (86.8%). Low cardiac output syndrome occurred in 8 cases and myocardial infarction occurred in 3 cases. The majority of the cases were treated successfully, but 5 patients died within one month after operation. Causes of death were as follows: myocardial infarction, constrictive pericarditis, cardiac tamponade, non-occlusive mesenteric ischemia and acute cardiac failure. Postoperative arrhythmia occurred mainly up to the third postoperative day. Low cardiac output syndrome occurred just after operation or on the first postoperative day. All cases of myocardial infarction occurred on the first postoperative day. The rate of occurrence of cardiocirculatory disturbances in aged patients (greater than or equal to 70) was significantly higher than other group (less than or equal to 69), (56.7%:38.1%, p less than 0.05). The rate of occurrence of cardiocirculatory disturbances in patients who had a history of hypertension or in patients with abnormal preoperative electrocardiographic findings were relatively higher than those in patients who had no history of hypertension or in patients with no abnormal preoperative electrocardiographic findings. The rate of occurrence of cardiocirculatory disturbances in patients who had undergone total resection of the thoracic esophagus was significantly higher than that in patients who had undergone partial resection of the thoracic esophagus (42.8%:23.8%, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Postoperative cardiac arrhythmias (author's transl)]

13 male patients suffering from arteriosclerotic heart disease and/or arterial hypertension were monitored continuously before and after vascular surgical procedures using an arrhythmia computer. Heart rate, paroxysmal supraventricular tachycardias, ventricular extrasystoles, ventricular tachycardias, ventricular fibrillation and prematurity index (QnQe/QTn) were recorded numerically. Ventricular arrhythmias were detected as follows preoperatively in 12 patients, after operation in all patients, paired ventricular extrasystoles or episodes of ventricular tachycardia were found in 5 cases before and in 7 after operation, ventricular fibrillation in one case. The incidence of ventricular dysrhythmias increased significantly (p less than 0.05) early after operation, as did the heart rate during the observed postoperative period (p less than 0.001). The prematurity index dropped below 1.0 during the two days following operation. This differed significantly from the preoperative value (p less than 0.05). The incidence of ventricular extrasystoles was related to postoperative myocardial infarction and heart failure (p less than 0.01), which occurred in 6 cases, with a lethal outcome in three. Only occasionally controlled by trained staff in a normal surgical ward the "Servomed Dysrhythmiemonitor" yielded reliable numerical results during the main part of the monitored period. In two cases it led to immediate detection and rapid institution of treatment of severe tachyar rhythmias.     

Aortocoronary artery graft during early and late phases of acute myocardial infarction

From April, 1968, to August, 1972, 30 patients received one to three emergency saphenous vein grafts during acute myocardial infarction. In all but 1 patient, acute myocardial infarction occurred while the patients were in the hospital awaiting coronary angiography or myocardial revascularization.The patients were divided into two groups: those in the early and those in the late phases of acute myocardial infarction, depending on the time interval between the onset of chest pain and operation. Twenty-four patients (early phase) received grafts within 10 hours after the onset of infarction, and 18 of these 24 patients underwent operation within 4 hours after infarction. Two patients included in this group sustained myocardial infarctions in the operating room during elective myocardial revascularization procedures; another patient was brought to the operating room following cardiac arrest and was supported by internal cardiac massage throughout the opening of the chest and cardiac cannulation. Six patients (late phase) received grafts from three to fourteen days after acute infarction because of postinfarction angina. Only 1 patient was in cardiogenic shock prior to operation.Two patients, both from the early phase group, died in the postoperative period; and 1 patient died seven months postoperatively from a noncardiac cause. Twenty-five of 27 surviving patients became asymptomatic, and 2 patients continue to have mild angina (Functional Class II). Sixteen patients with 24 grafts were restudied in the postoperative period, and 22 of the grafts were found to be patent.This experience suggests that early operative intervention in acute myocardial infarction by the saphenous vein graft technique is beneficial to the patient. The rationale of revascularization in the early phase of acute myocardial infarction is to minimize the area of muscle necrosis by increasing perfusion to the ischemic myocardium around the infarct.     

Predictors of postoperative ventricular dysrhythmias: a multivariate study

Postoperative ventricular dysrhythmias were studied to document their incidence after coronary bypass grafting and to identify risk factors for their development with the hope of finding a subgroup of patients who might benefit from postoperative, prophylactic drug therapy. One-hundred-nine patients who were undergoing urgent or elective coronary bypass grafting were studied, prospectively. Twenty-five of 109 patients (23%) developed significant postoperative ventricular dysrhythmias that required counter-shock or drug intervention. Seven of eight instances of sustained ventricular tachycardia, the most serious dysrhythmia, occurred within 36 hours of operation. There was no postoperative mortality related to these dysrhythmias. Serious postoperative complications, such as stroke, hemorrhage, or myocardial infarction, were decreased in patients with ventricular dysrhythmias versus those without (8% versus 16%, p = 0.053 for the Fisher's exact test statistic). Univariate statistical analysis was performed using 15 patient variables and revealed that advanced age (p = 0.008 for the unpaired t test), failure to use an internal mammary artery conduit (p = 0.03 for the two-tailed Fisher's exact test), and development of postoperative atrial dysrhythmias (p = 0.02 for the two-tailed Fisher's exact test) were significantly more common in patients with postoperative ventricular dysrhythmias. Variables such as previous myocardial infarction, ejection fraction less than 50%, prolonged operative time, perioperative myocardial infarction, or fewer number of vessels bypassed were not significantly increased in patients with dysrhythmias (the statistical power for these "negative" results was greater than 0.8).(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative analysis of myocardial revascularization on left ventricular diastolic function

To evaluate the effects of myocardial revascularization on left ventricular diastolic function, we studied three groups of subjects. Group I consisted of 10 patients without any previous myocardial infarction. Group II consisted of 10 patients with previous myocardial infarction. The control group consisted of 8 normal subjects, all with no evidence of cardiac disease as determined by cardiac catheterization. Left ventricular diastolic function was assessed by maximum negative dp/dt, constant T, diastolic compliance and 1/3 fractional filling before and after surgical revascularization. (1) Constant T, maximum negative dp/dt and diastolic compliance: There was no significant difference among groups I, II and the control group preoperatively, and the variables were not improved postoperatively. (2) 1/3 fractional filling: 1/3 fractional fillings in groups I and II were significantly lower (p less than 0.05, p less than 0.01) than the control group preoperatively, and it was significantly improved in group I, but unchanged in group II postoperatively. In conclusion, myocardial revascularization improves left ventricular diastolic function in the patients without previous myocardial infarction. The effects of myocardial revascularization, however, in the patients with prior myocardial infarction do not bring about an enhancement of left ventricular diastolic function.     

Emergency aortocoronary bypass after failed angioplasty

One thousand two hundred fourteen percutaneous transluminal coronary angioplasties were performed over a 38-month period. Sixty patients required immediate emergency coronary artery bypass grafting after angioplasty failure; 7 of these had evidence of acute myocardial infarction before angioplasty and were excluded from the study. Of the 53 patients remaining, 27 (51%) had electrocardiographic and enzyme evidence of postoperative myocardial infarction. Two patients died (4%), and 10 had postoperative complications (19%). No statistical significance was noted comparing age, sex, incidence of prior myocardial infarction or myocardial dysfunction, time for revascularization, or average number of grafts completed in those with single-vessel (n = 21) versus multiple-vessel (n = 32) coronary artery disease. Postoperatively, those with multiple-vessel disease required intraaortic balloon pump support (p = 0.06) and antiarrhythmic medications more frequently than single-vessel patients (p less than 0.01) and had a higher complication rate (p less than 0.05). Although not reaching statistical significance, the data also suggest a higher death and postoperative myocardial infarction rate in patients with multiple-vessel disease. Emergency coronary artery bypass grafting after failed percutaneous transluminal coronary angioplasty carries a higher morbidity and mortality than elective coronary artery bypass grafting, particularly for patients with multiple-vessel coronary artery disease.     

Myosin: a highly sensitive indicator of myocardial necrosis after cardiac operations

Plasma levels of ventricular myosin fragments, determined with monoclonal antibodies to myosin heavy chains, were studied in 27 patients after cardiac operations (17 aorta-coronary bypass grafts and 10 valve replacements) to assess their possible role as a marker of perioperative myocardial necrosis. Five patients had perioperative myocardial necrosis after aorta-coronary bypass grafts as indicated by changes in the electrocardiogram and elevated levels of the MB isoenzyme of creatine kinase. Six more patients were also studied after thoracic operations performed by the same sternotomy approach. After cardiac operations, myosin levels increased from postoperative day 3 and reached peak values on day 7. Peak myosin values in patients with perioperative myocardial necrosis after aorta-coronary bypass grafting were significantly higher than in patients after an identical operation but without perioperative myocardial infarction (3793 +/- 592 versus 369 +/- 47 ng/ml; p less than 0.001). These results suggest that plasma myosin is a sensitive marker of myocardial necrosis. Furthermore, peak plasma levels of ventricular myosin after coronary bypass grafting without myocardial infarction (mean value 369 +/- 47 ng/ml) were not significantly different from peak levels after thoracic operations (mean value 253 +/- 52 ng/ml), whereas they were significantly higher after valve replacement (mean value 794 +/- 149 ng/ml; p less than 0.01). These results indicate that a certain degree of myocardial necrosis occurs during value replacement that is undetectable by the usual diagnostic criteria for perioperative myocardial infarction. We conclude that the plasma level of ventricular myosin fragments is a more specific and accurate marker of perioperative myocardial necrosis than changes in the electrocardiogram or elevated creatine kinase MB levels. Therefore the detection of myosin fragments, which appear in the serum on the third day after cardiac operations, may be useful for precise comparisons of different techniques of myocardial protection.