Successful management of left ventricular rupture following myocardial revascularization

Left ventricular (LV) rupture is a common cause of death following myocardial infarction, but it is rarely noted following coronary bypass surgery. This is true despite the increasing number of coronary bypass operations performed for postinfarction angina, often following transmural infarction. A 59-year-old woman underwent successful repair of left ventricular free-wall rupture that occurred after coronary surgery performed for postinfarction angina. To our knowledge, this is the first report to establish the feasibility of successful surgical repair of left ventricular free-wall rupture in the postoperative patient with tamponade or intrathoracic bleeding.     

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.     

Predicting outcome after myocardial revascularization in patients with left ventricular dysfunction

In order to identify the risk factors which could predict outcome after coronary artery bypass grafting in patients with left ventricular dysfunction, 80 consecutive patients with an ejection fraction ≤30%, who underwent isolated coronary artery bypass grafting at the authors' centre between January 1994 and May 1996 were evaluated. Preoperatively, mean(s.d.) ejection fraction was 27.1(3.8)%, 56 patients (70%) had angina, and 56 (70%) were in New York Heart Association (NYHA) functional class III or IV. There were five operative deaths, with a hospital mortality rate of 6.3%. Significant risk factors for hospital death were NYHA class IV, preoperative ventricular arrhythmias and left ventricular end-diastolic volume index >110 ml/m². At mean follow-up of 15(7) (range 6–30) months, there were six late deaths, five of which were from cardiac causes. Actuarial survival rate at 2 years was 82(5)% and freedom from cardiac death 84(5)%. Risk factors for overall mortality from cardiac causes were preoperative grade 2 mitral regurgitation, associated with left ventricular dilatation, and renal dysfunction (creatininaemia ≥180 μmol/l). At follow-up, mean ejection fraction was 37.5(8.4)%, and the overall functional status had improved: 12 patients (18%) had angina and eight (12%) were in NYHA class III and IV. Myocardial revascularization in patients with left ventricular dysfunction can be performed with acceptably low operative risk, good survival rate at 2 years, and functional status improvement. Patients with extensive ventricular dilatation, associated with significant mitral regurgitation, have a lower life expectancy and less functional benefits from coronary artery bypass grafting. These patients are better treated by cardiac transplantation.     

Right ventricular function in patients with reduced left ventricular function undergoing myocardial revascularization.

Complex interrelationships exist between the right (RV) and the left ventricles (LV). Therefore, in 30 consecutive patients with reduced LV function (left ventricular ejection fraction [LVEF]) less than 40% undergoing myocardial revascularization, RV hemodynamics were studied from the beginning of anesthesia until the end of the operation. The data were compared with 30 consecutive patients with normal LVEF (greater than 70%). Ventricular function was assessed during left heart catheterization, which was carried out within 1 month of the operation. In addition to standard hemodynamic variables, RV ejection fraction (RVEF), RV end-diastolic volume (RVEDV), and RV end-systolic volume (RVESV) were monitored by the thermodilution technique. The two groups did not differ preoperatively with regard to RVEF, pressure (MAP, PAP, PCWP, RAP, RVPsyst, RVEDP), cardiac index (CI), and volume variables (RVESV, RVEDV). However, when the group with preoperatively reduced LVEF was subdivided into patients with severely reduced LVEF (less than 30%; n = 14; mean value 25.1%) and patients with moderately reduced LVEF (30%-40%; n = 16; mean value 37.3%), RVEF was significantly lower in the patients with a LVEF below 30% throughout the entire investigation period. RVEDV and RVESV were significantly higher in these patients. In conjunction with the lower RVEF and normal PAP, this suggests reduced RV function. It can be concluded that a severely reduced preoperative LVEF (less than 30%) may also be associated with impaired RV function.     

Early and late determinants of survival after surgery of left ventricular aneurysm

The fate of 103 patients consecutively operated upon for chronic left ventricular aneurysm between 1978 and 1986 was examined with a multivariate statistical approach to verify the operative indications and results. In the early risk phase, up to 39 days after operation, 15 patients (15%) died. Mortality was mostly due to a low output syndrome and was significantly related to older age and to functional (NYHA) and anginal (CCS) class. In the late risk phase, starting 1.9 years after surgery, 9 patients died (10%) and the significant risk factors were anterior aneurysm and older age at operation. Actuarial survival curves showed 82% survival at 5 years and 61% at 9.5 years. In 25 patients older than 50 years and with an anterior aneurysm, these rates were 51% and 34%, respectively. Improved functional class was observed in 87% of the patients interviewed, but 30% complained of angina or new infarctions. Survival free of ischemia was 64% at 5 years and 13% at 9.5 years. This development of ischemic recurrences was significantly related to older age and to incomplete revascularization despite multiple grafts. These results suggest modification of the grafting policy and of the techniques of repair in identified high-risk subsets.     

Intracoronary shunt prevents left ventricular function impairment during beating heart coronary revascularization.

OBJECTIVE: Beating heart coronary revascularization is becoming increasingly popular world-wide. Temporary occlusion of the coronary artery is often required in order to perform the anastomosis. An alternative method to maintain perfusion is to use an intracoronary shunt. In this study, we monitored global left ventricular function and regional wall motion in the presence or absence of a shunt using transesophageal echocardiography (TEE). METHOD: Left ventricular wall motion score index (WMSI), wall motion score (WMS) in the left anterior descending (LAD) coronary artery territory, and ejection fraction (EF%) were measured by multiplane TEE during construction of the left internal mammary artery (LIMA)-LAD coronary artery anastomosis in 40 patients undergoing revascularization with or without the use of a shunt. WMSI was assessed preoperatively, 1, 3 and 6 min during the construction of the anastomosis and after 5 min of reperfusion. WMS was assessed at 6 min during anastomosis and after 5 min of reperfusion. EF% was calculated preoperatively, 5 min into the construction of the anastomosis, and 5 min after reperfusion. RESULTS: During construction of the anastomosis, when the shunt was used, there were no changes in WMSI, WMS in the LAD territory or EF%. A significant decline in these parameters was seen in the group in which the shunt was not used, although on reperfusion all the values returned to baseline control. CONCLUSION: (i) occlusion of the LAD to perform the anastomosis results in temporary impairment in left ventricular function with complete recovery on reperfusion; (ii) the use of an intracoronary shunt presumably by maintaining myocardial perfusion prevents deterioration in ventricular function; (iii) from this data it seems therefore advisable to use an intracoronary shunt in patients with unstable angina, poor left ventricular function, or in cases in which a longer time to perform the anastomosis is anticipated.     

Improved functional results following myocardial revascularization in patients with left ventricular dysfunction

Between February 1978 and October 1982, 40 patients with preoperative ejection fraction (EF) of 0.35 or less underwent aortocoronary bypass. An average of 3.1 saphenous vein grafts per patient were inserted and revascularization was considered complete in 33 (82%) of the subjects in the group. Mean follow-up period was 29 months (range 12-65 months). Early mortality was 5% (2 patients) and there were seven late deaths (3 cardiac and 4 non-cardiac). The five-year cardiac actuarial survival rate was 74% +/- 13% (+/- SEM). Angina has improved in 29 (94%) of the 31 long-term survivors with 23 (74%) being totally asymptomatic. Twenty-two of the long-term survivors performed an exercise test at the end of their follow-up period. These tests revealed that bypass surgery in such patients results in significantly enhanced myocardial oxygen consumption with concomitant increase in effort level and duration. The exercise ability is probably directly related to the degree of revascularization.     

Myocardial revascularization for severe left ventricular dysfunction. Factors influencing early and late survival

The results of coronary bypass surgery have been assessed in 102 patients with severe left ventricular dysfunction who had a preoperative left ventricular ejection fraction of ⩽0.35 (mean(s.e.m.) 0.29 (0.01)). Independent risk factors influencing operative mortality were obesity (P = 0.0290) and the need for preoperative intra-aortic balloon counterpulsation (P = 0.0010). Cox regression analysis using as its end-point ‘cardiac-related death’ demonstrated three variables; the need for preoperative intra-aortic balloon counterpulsation (P = 0.001), advanced age (P = 0.011), and obesity (P = 0.036). In a subset of 43 patients who did not have these risk factors, the 4-year cardiac-related death rate was 95.1 (3.4)%. The operative mortality and long-term survival can be expected to be satisfactory in patients with severe left ventricular dysfunction, provided they have a viable myocardium rather than myocardial fibrosis.     

Complete myocardial revascularization and sutureless technique for left ventricular free wall rupture: clinical and echocardiographic results

Left ventricular free wall rupture (LVFWR) is one of the most dramatic complications of myocardial infarction. We present our mid-term clinical and echocardiographic results of LVFWR with patch and complete myocardial revascularization on viable tissue. From August 2000 to July 2005, 9 patients underwent surgery for LVFWR. Mean age was 68+/-S.D. 9.3 years. Mean interval time between AMI and LVFWR was 122.2+/-154.9 h. All patients presented for emergency surgery with cardiac tamponade at echocardiography. Three patients received IABP preoperatively. Eight had coronarography. Effective control of bleeding was achieved in all cases with a Teflon patch applied with Bioglue. Four patients had myocardial revascularization, all in ECC; two of them with cross-clamping. There was no operative death. Mean follow-up was 38.8+/-22.2 S.D. months. One further death occurred from myocardial infarction. All patients were in NYHA I-II. Survivors had follow-up transthoracic echocardiography: all patients had preserved left ventricular function with absence of restricted motion. There was no evidence of mitral regurgitation. Sutureless covering technique for LVFWR is related to excellent early and long-term clinical and echocardiographic results. Complete coronary artery bypass grafting improves long-term symptom-free survival. We have demonstrated that ECC and cross-clamping do not affect early survival.     

Prevention of ventricular fibrillation after myocardial revascularization

Ventricular fibrillation during reperfusion after aortic cross-clamping for coronary artery bypass grafting may cause subendocardial injury. We investigated the use of lidocaine to prevent ventricular fibrillation during this period. In a blind, prospective, randomized trial, 91 consecutive patients undergoing elective coronary artery bypass graft procedures were given lidocaine (2 mg/kg) or normal saline immediately before removal of the aortic cross-clamp. The groups were similar with respect to demographic, clinical, and intraoperative variables. Myocardial preservation techniques were similar in both groups. Of 47 patients receiving lidocaine, 38 recovered a supraventricular rhythm without ventricular fibrillation, compared with only 5 of 44 patients in the control group (p less than .001). When ventricular fibrillation occurred, patients in the control group required a greater number of direct-current countershocks (2.31 versus 1.86) to convert to sinus rhythm. Transient heart block, requiring temporary pacing, developed in 3 patients in the lidocaine group, compared with 1 patient in the control group. There was no significant difference between the groups in the requirement for perioperative inotropic support (6 of 47 versus 6 of 44) or the number of myocardial infarctions (2 of 47 versus 1 of 44), and there were no deaths in either group. Lidocaine infusion immediately before removal of the aortic cross-clamp significantly reduces the incidence of ventricular fibrillation during the reperfusion period after cardiopulmonary bypass.     

Resection of postinfarction left ventricular aneurysm with and without revascularization

Twenty-four patients had resection of their ventricular aneurysm and 29 had resection plus revascularization. Sixty percent of the patients received no blood in the heart lung machine during surgery or at any time during hospitalization. One of 24 patients with ventricular resection and two of 29 patients with resection plus revascularization died during hospitalization, for an overall mortality of 5.7%. Fifty of the 53 patients had an ejection fraction of 0.4 or less and 23 of these had an ejection fraction of 0.2 or less. Survival rate was 75.5% at four years for all 53 patients compared to only 12% of patients alive at five years with medical treatment. For the patient with a large ventricular aneurysm, resection and myocardial revascularization can be performed with a low risk even for the patient with poorly functioning residual myocardium.     

Effects of coronary revascularization on infarcted myocardial regions--evaluation on postoperative left ventricular regional wall motion during exercise

In order to determine the effects of coronary revascularization for infarcted regions on postoperative left ventricular function and regional wall motion, we studied first-pass radionuclide angiography at rest and during exercise before and after operation in 18 patients with previous myocardial infarction. Preoperative mean value of left ventricular ejection fraction (LVEF) was significantly decreased during exercise from 56.8 +/- 14.1% to 46.1 +/- 15.5% (p less than 0.01). Postoperatively, there was no change of the values between at rest and during exercise: 53.6 +/- 14.1% versus 51.9 +/- 15.7%. Postoperative mean LVEF during exercise was significantly higher, compared with that of preoperative LVEF (p less than 0.05). Mean regional ejection fraction of infarcted regions was significantly decreased during exercise from 66.0 +/- 15.0% to 56.1 +/- 15.8% (p less than 0.01) before operation. However, there was no significant change in values between at rest and during exercise after operation: 65.4 +/- 13.9% versus 61.8 +/- 14.5%. Mean postoperative regional ejection fraction during exercise was significantly higher, compared with preoperative regional ejection fraction after operation (p less than 0.05). These results might be indicated that regional wall motion of the infarcted regions with ischemia enhanced by exercise preoperatively can be definitely improved by coronary revascularization.     

Improvement of severely reduced left ventricular function after surgical revascularization in patients with preoperative myocardial infarction.

In recent years, two pathophysiological conditions--stunned and hibernating myocardium--have been described showing how function may be depressed in myocardium that remains viable. The aims of the present study were postoperative assessment of LV function at rest and during exercise after CABG in patients with established previous myocardial infarction and impaired preoperative LV function and evaluation of preliminary experience with positron emission tomography (PET) in the preoperative identification of reversible ischaemic myocardium and its predictivity in postoperative functional improvement. We studied 23 patients with preoperative LV function under 45%. Echocardiography and complete heart catheter were performed pre- and postoperatively. PET was performed in all patients preoperatively. In 21 patients with patent grafts, CABG significantly improved systolic and diastolic function during exercise and at rest. EF improved from 34% +/- 14% to 52% +/- 11% at rest and from 31% +/- 14% to 58% +/- 13% during exercise (P less than 0.01). Time constant of diastolic relaxation was significantly reduced after revascularization. In 2 patients with pathological findings on postoperative coronarangiography, EF remained unchanged. Both global and regional contractility improved following surgery. Regional analysis indicated that improved EF at rest occurred in regions developing ischaemia during exercise before CABG and in regions showing typical mismatch in 82Rubidium-2-fluoro-2-desoxyglucose suggesting the presence of hibernating myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Role of myocardial revascularization in postinfarction ventricular septal rupture

BACKGROUND: Postinfarction ventricular septal rupture requires urgent closure. The role of systematic coronarography and coronary revascularization needs clarification. METHODS: Fifty-four patients who underwent patch closure of postinfarction ventricular septal defect were reviewed. A coronarography had been systematically and myocardial revascularization selectively (when significant coronary artery stenosis existed) performed. RESULTS: No patient died or deteriorated during coronarography. Twenty-six patients showed no coronary artery disease besides the infarct-related artery, and 28 had associated disease. Threatened myocardial territories were revascularized usually with venous grafts (mean number of distal anastomosis, 2.5). Operative mortality was 19% and 32% (p = 0.36) and late mortality 43% and 53% (p = 0.75) in patients without and in patients with associated coronary artery disease, respectively. Survival curve in both group was similar, at least up to 8 years after operation. CONCLUSIONS: Myocardial revascularization controlled the added risk of associated coronary artery disease in the postoperative period and in median term. A coronarography should be performed in all patients who can be stabilized hemodynamically and myocardial revascularization performed in case of significant stenosis.     

Off-pump myocardial revascularization in a diabetic patient with severe hemophilia B and impaired left ventricular function: hematological and operative strategies

Coronary surgery with diabetes and severe hemophilia B is a challenging situation requiring specific and adequate therapeutic considerations. We herein report the case of a 52-year-old diabetic patient with severe factor IX deficiency and impaired ventricular function, who was scheduled for myocardial revascularization because of exertional angina and recurrent myocardial infarctions following infusions of factor IX concentrate. The patient underwent a successful off-pump direct myocardial revascularization with neither hemorrhagic nor thrombotic complications. Hematological protocols and operative strategies are assessed and discussed.