Severe Left Ventricular Impairment Research Articles

Left ventricular function and endomyocardial biopsy in early and advanced dilated cardiomyopathy

We evaluated left ventricular function and endomyocardial biopsy in 20 patients with early and advanced dilated cardiomyopathy, with the purpose of assessing the correlation between histologic variables and systolic and diastolic filling indexes. Group 1 included 10 patients with no clinical history of heart failure and left ventricular ejection fraction ≥45% and group 2, 10 patients with a clinical history of heart failure and left ventricular ejection fraction <45%. Group 1 showed lower left ventricular end-systolic and end-diastolic volumes indexes (49±14 versus 86±23 ml/m 2, P<0.001; 98±25 versus 127±35 ml/m 2, P=0.049), higher left ventricular ejection fraction (50±4 versus 32±4%, P<0.001) and lower coefficient of variation of percentage shortening of left ventricular transverse hemiaxes (0.3±0.1 versus 0.5±0.1, P=0.001) compared with group 2. Group 1 had higher A wave peak velocity (78±18 versus 60±20 cm/s, P=0.048), lower E/A ratio (0.9±0.3 versus 1.5±0.6, P=0.02) and slower E wave deceleration time (204±51 versus 155±50 ms, P=0.047) compared with group 2. Semiquantitative histologic scores did not differ significantly between groups. There was no significant correlation between histologic variables and left ventricular systolic and diastolic indexes. Thus, dilated cardiomyopathy shows borderline to severe left ventricular systolic impairment and distinct left ventricular diastolic filling abnormalities, according to the clinical stage. This study suggests a marked dissociation between histologic findings and functional abnormalities in early and advanced dilated cardiomyopathy.

Hibernating myocardium: clinical and functional response to revascularisation.

We assessed the effects of coronary bypass grafting on left ventricular (LV) function, exercise capacity and symptom profile in patients with LV impairment and evaluated the role of identifying myocardial hibernation in a prospective non-randomised study. Of 120 patients screened, 47 patients with LV ejection fraction < 35% and three vessel coronary artery disease were studied. All underwent stress/redistribution and separate day rest/redistribution T1-201 imaging together with cine MRI at enrolment, and cine MRI at follow-up. Group 1, 30 patients undergoing bypass surgery, underwent symptom limited treadmill exercise testing with peak VO2 measurement, and symptom profile evaluation less than 3 months before, and 3-6 months after operation. Revascularisation was assessed by post-operative T1-201 imaging and repeat coronary angiography. Group 2, 17 patients treated on medical therapy alone underwent symptom profile assessment at enrolment and follow-up for those who survived. Segmental hibernation was defined as the equivalent of greater than 50% of maximal T1-201 uptake where wall motion was severely impaired on resting imaging. Patients were considered to be hibernating where two of nine LV segments fulfilled these criteria. In group 1, five patients died (17%), peri-or post-operatively, two defaulted and 23 attended follow-up studies. In group 2, three patients died prior to follow-up (18%). In the surgical group there was an increase in mean LVEF from 24.0 +/- 8% to 29.7 +/- 11% (P < 0.05) while in the medical group there was a fall from 25.7 +/- 10% to 20.6 +/- 8% (P < 0.05). In group 1, the mean NYHA dyspnoea grade improved from 2.7 to 1.4 while in the medical group it was unchanged, 2.6 to 2.5. In patients with myocardial hibernation identified pre-operatively, 18/19 (95%) improved LVEF after CABG compared with 2/4 (50%) of patients without hibernation. 17/19 (86%) patients with hibernation improved NYHA dyspnoea class compared with 2/4 (50%) of patients without. 60/93 (65%) of hibernating segments improved function after revascularisation while 47/53 (89%) hibernating segments showed no improvement on medical therapy alone. In patients with severe LV impairment with myocardial hibernation, coronary artery bypass grafting improves both global and regional systolic LV function, and symptom profile. Medical treatment of patients with LV impairment and myocardial hibernation does not improve LV contractile function or symptoms. Both surgical and medical therapy carry a high mortality rate.

Hospital morbidity and mortality after myocardial revascularisation surgery: current changes in risk factors.

To identify the operating risks for mortality and morbidity in patients undergoing aortocoronary bypass surgery, the data of 514 myocardial revascularisation procedures performed consecutively between January 1991 and December 1992 were analysed; 73.2% of the patients had associated diseases and 59.3% had suffered one or more previous myocardial infarctions. The mean ejection fraction of the population as a whole was 52.2 +/- 13. In 10.5% of the cases there was severe left ventricular (LV) function impairment with a mean ejection fraction (EF) of 30.2 +/- 4.4 (range 20-35). A major preoperative complication occurred in 8.2% of the entire population and 68.8% of the patients undergoing emergency surgery. Surgery was elective in 72.7% of the cases, urgent in 15.4% and emergency in 11.9%. Hospital mortality was 4.1% (CL 3.2-4.9). In the group of electively operated patients, mortality was 2.7% (CL 1.8-3.5), with no statistically significant difference (P = 0.943) from the mortality observed in the patients undergoing urgent surgery [2.5% (CL 0.8-4.1)]. The mortality in both groups was statistically different (P = 0.0001 and P = 0.008) from that of the patients undergoing emergency surgery [14.7% (CL 10.1-18.9)]. Perioperative acute myocardial infarction occurred in 5.4% of the patients (CL 4.4-6.4), in three cases resulting in death [10.7% (CL 4.8-15.8)]. Fourteen of the acute myocardial infarctions (AMI) occurred in the 42 patients undergoing emergency surgery for acute coronary occlusion (33.3%). A percentage of 18.7% of the 493 surviving patients suffered a postoperative complication.(ABSTRACT TRUNCATED AT 250 WORDS)

Milrinone and postoperative pulmonary hypertension

C LINICAL EXPERIENCE in both Europe and North America suggests that an increasing number of adult patients presenting for cardiac surgery are at risk of pulmonary hypertension. There are a number of factors responsible for this, not least the increasing age of the surgical patient population, and the fact that reoperation and cardiac surgery in very high risk cases are increasingly being undertaken. There is no doubt that the effective management of perioperative pulmonary hypertension remains a major challenge, but it should not be overlooked that optimizing the state of the pulmonary vasculature, and hence of right ventricular function, may have a significant beneficial effect in patients with not only borderline pulmonary hypertension but severe left ventricular impairment. In this situation right ventricular function may have a critical impact on left ventricular diastolic and systolic performance, and in this sense the treatment of the cardiac surgical patient should focus on more than simple pulmonary hemodynamics. Both physiologic and pharmacologic factors may have a major impact on the pulmonary vasculature. Many of the agents used in current practice are identified in this issue (see Dr Hines’ article). In the experimental setting, it is of course possible to strictly control many of the physiologic factors involved, but in clinical practice and research in humans, many of the factors may only be modified to a limited extent, and so the effectiveness of any drug therapy has to be viewed within the context of the clinical environment under study. In this article the experimental and clinical data currently published on the effects of milrinone on the pulmonary circulation are reviewed, with the aim of identifying any potential role of this important new compound in the management of postoperative pulmonary hypertension.

Rapidly progressive deteriorated left ventricular wall motion associated with tetanus: A case report.

A case of tetanus accompanied by severe reversible left ventricular motion impairment is reported. Emergent coronary angiography showed no abnormalities and large akinesis was present on left ventriculography. The plasma catecholamine level was not too high in the acute phase, therefore it is thought that the cause of this depressed left ventricular wall motion abnormality was due to some metabolite derived from tetanus.

Coronary arterial surgery in the elderly: its effect in the relief of angina

Financial and other constraints, such as operative risk, may prevent older patients being considered for coronary arterial bypass grafting. Grafting was performed in 315 elderly patients (244 males, 71 females, age 65–79, mean 69 years) between 1981–1986. All patients had limiting angina, 38% had rest pain, 90% were housebound and 80% had triple-vessel disease. Impairment of left ventricular function was absent in 46%, mild in 20%, moderate in 23% and severe in 10% of patients. Grafts (saphenous vein or internal mammary artery) were inserted into 3 vessels (52%), 4 vessels (42%), 5 vessels (6%), 6 vessels (0.5%). Death during surgery occurred in 1.6% and a further 3.5% of patients died later during the same admission (70% of deaths were among the 33% with preoperative moderate or severe left ventricular impairment). Surgical complications included myocardial infarction (8%), cerebrovascular accident (1%), transient cerebral vascular ischaemia (5%), chest infection (10%) and wound infection (4%). Median stay on the intensive care unit was 1 day and median total hospital stay 12 days. 299 patients therefore survived to leave hospital and follow-up data are available for 217 (72%) of these. 96% were subjectively improved by surgery, 88% being free of angina on no antianginal drugs a median of 72 weeks (range 8–307) and a further 8% not limited by angina on medical therapy a median of 85 weeks (range 9–302) after surgery. We conclude that coronary arterial surgery is an effective treatment for angina in the elderly. This will have consequences for future resource allocation if the elderly are not to be denied effective therapy because of financial rather than clinical restraints.

Myocardial infarction and normal coronary arteriography: A 10 year clinical and risk analysis of 74 patients

Myocardial infarction with normal coronary arteries was identified in 74 patients with a mean age of 43 years (range 19 to 66). A mean follow-up period of 10.5 years after documented myocardial infarction and 8.6 years after cardiac catheterization was obtained. The survival rate was 85% (n = 63). There were no statistical differences in age or clinical risk factor prevalence between survivors and non-survivors. Moderate (55%) to severe (27%) left ventricular impairment was more common in nonsurvivors. Nine of 11 deaths were cardiovascular, 6 were sudden and 8 occurred in patients with moderate to severe global left ventricular impairment. Seventy-six percent of survivors were asymptomatic and 86% were fully active at follow-up. Two survivors and three nonsurvivors experienced a second myocardial infarction.The clinical risk factors of the study group (Group I) were compared by age, sex and year of catheterization with risk factors in two matched groups. Group 11 consisted of 74 patients with coronary occlusive disease and myocardial infarction and Group III consisted of 148 patients with normal arteriograms. Group I differed from Group II in having fewer clinical risk factors (p = 0.01 to <0.0001). Cigarette smoking did not differ significantly between Group I(72%) and Group II (69%) but was less common in Group III (45%) (p < 0.001). Hormone therapy or the peripartum state was more common in women in Group I (34%) than in women in Group III (14%) (p = 0.03).These data suggest a favorable 10 year survival rate in patients with myocardial infarction and normal coronary arteries that appears to depend on residual left ventricular function. Smoking or therapeutic hormone use, or both, may be risk factors.

Medical versus Early Surgical Therapy in Patients with Triple-Vessel Disease and Mild Angina Pectoris: A CASS Registry Study of Survival

Results of coronary artery bypass grafting were evaluated in 856 nonrandomized patients in the Coronary Artery Surgery Study (CASS) registry with mild angina (Canadian Cardiovascular Society Classes I and II) and three-vessel disease, defined as 70% or more stenosis in the proximal or middle segment of the three major coronary arteries. There were 413 patients with medical therapy and 443 with early operation. Patients with delayed operation were kept in the medical group for analysis. Six-year survival adjusted for left ventricular (LV) function and number of proximal stenoses was 67% for medical and 84% for surgical patients ( p < 0.0001). Patients with normal LV function had equal survival with medicine or surgical intervention. Those with mild or moderate LV dysfunction (CASS LV wall motion score 6 to 9 and 10 to 15, respectively) and at least one proximal stenosis (the dominant right coronary artery) had increased probability of being alive at six years with surgical treatment. In patients with severe LV impairment (LV score higher than 15) and in those whose only proximal stenosis of 70% or more (in three-vessel disease) was located in the left anterior descending coronary artery, increased survival with surgical treatment could not be demonstrated. This is a nonrandomized observational study with the limitations of such studies: the need to adjust for differences in baseline traits between medical and surgical groups and the possibility of an unrecognized imbalance in baseline characteristics. In a Cox analysis of variables influencing outcome, early surgical treatment was an independent predictor of survival with 43% the risk of medical treatment (95% confidence range: 29 to 62%). Adjustment by propensity analysis to reduce selection bias from known differences in baseline variables did not alter results.

Limitations of quantitative phase analysis of radionuclide angiograms for detecting coronary artery disease in patients with impaired left ventricular function

Phase analysis of radionuclide ventriculograms is used for identifying ischemic wall motion abnormalities. Myocardial segments with an abnormal phase, that is, delayed onset of wall motion, can be localized on a phase distribution image, and the synchronicity of left ventricular (LV) wall motion can be assessed from a histogram of LV phase distribution. The standard deviation of the LV peak on this histogram (SDP-LV) describes the width of the peak and is used as an index of the synchronicity of wall motion. We examined in this study the sensitivity of SDP-LV for identifying coronary artery disease (CAD) and its specificity in patients with normal and various degrees of LV impairment. A total of 84 patients were studied. Forty-five patients had CAD and 39 had congestive cardiomyopathy or valvular heart disease. Patients were grouped according to their LV ejection fraction (EF). In group I (37 patients) resting LVEF was equal to or greater than 50%, in group II (24 patients) it ranged from 35% to 50%, and in group III (23 patients) it was less than 25%. SDP-LV was highly specific in groups I and II for CAD with sensitivities of 48% and 89% at rest that increased with exercise to 88% and 100%. In group III patients, SDP-LV remained highly sensitive but was no longer specific for CAD. Therefore, in severe LV impairment, phase analysis does not aid in distinguishing CAD from other causes of ventricular dysfunction. By contrast, phase analysis is highly sensitive and specific for CAD in patients with normal or moderately depressed LV function.

Effects of intravenous disopyramide on myocardial function in patients with different degrees of cardiac failure.

The effects of intravenous disopyramide phosphate on myocardial function were evaluated by non-invasive indices of cardiac performance (systolic time intervals, STI) in 15 patients with atherosclerotic heart disease and different degrees of cardiac failure. Disopyramide (1.5 mg/Kg) was given intravenously over a period of 5 min. This drug induced in patients in I-II classes of NYHA a significant decrease of LVETc, while PEP, ICT, and PEP/LVET ratio rose significantly. STI were affected much more markedly in patients in III-IV classes of NYHA. Particularly affected were contractility indices (PEP, ICT, PEP/LVET), which were reduced significantly more in patients in III-IV classes as compares to patient in I-II classes. In contrast, LVETc, which correlates to stroke volume and cardiac output, was similarly worsened by the drug in the 2 groups of patients. Therefore, this study shows that disopyramide has relevant depressant effects on myocardial performance, simultaneously reducing stroke volume and contractility, and that the effect on contractility is more marked in patients with severe left ventricular impairment.

The Importance of Myocardial Protection in Combined Aortic Valve Replacement and Myocardial Revascularization

To determine the importance of different methods of myocardial protection for combined aortic valve replacement and coronary revascularization, we analyzed the records of 82 consecutive patients who underwent the combined procedure between 1973 and 1978. Sixty-three (77%) had angina and 63 (77%) were in New York Heart Association Functional Class III or IV. Moderate to severe left ventricular impairment was present in 59%, and the mean number of diseased vessels was 1.9 per patient. Group I consisted of 18 patients with intermittent ischemia, almost all of whom had operation between 1973 and 1976. Group IIa consisted of 24 patients operated on between 1973 and December, 1976, with coronary perfusion, and Group IIb had 18 patients in whom a similar technique was used in 1977 and 1978. Group III consisted of 22 patients operated on in 1977 and 1978 in whom cold chemical cardioplegia was used. The early mortality (<30 days) for Group I was 50% and for Group IIa 29%. There were no deaths in Group IIb and Group III. The incidence of perioperative myocardial infarction was 21% in Group I, 6% in Group IIa, 11% in Group IIb, and zero in Group III. The incidence of cardiogenic shock requiring prolonged inotropic support and intraaortic balloon counterpulsation was significantly less in Group III (9%) than in Group IIb (50%) ( p < 0.05). If other manifestations of myocardial injury, such as perioperative infarction and cardiogenic shock requiring intraaortic balloon counterpulsation or inotropic support, are taken into consideration, cold chemical cardioplegia appears to provide better myocardial protection than coronary perfusion of the fibrillating heart.

Natural history of severe proximal coronary artery disease as documented by coronary cineangiography

Studying the natural history of patients with severe proximal coronary arterial lesions may assist evaluation of coronary revascularization surgery. We reviewed the mortality statistics of 469 patients with 80 to 100 percent occlusive lesions in the proximal coronary tree as diagnosed by selective angiography. Only patients with normal or moderately impaired left ventricular function were included in the study; patients with severe cardiomegaly, congestive heart failure or severe left ventricular impairment by left ventriculography were excluded. Follow-up periods ranged from 6 to 11 years for 178 patients with single vessel disease, 177 with double vessel disease and 114 with triple vessel disease. Patients with isolated disease of the left anterior descending artery had a 4 percent average yearly attrition rate or a 6 year mortality rate of 25.5 percent (17 of 69). Those with isolated disease of the right coronary artery demonstrated only a 2.3 percent yearly attrition rate or a 14 percent mortality rate in 6 years (11 of 77). Patients with double and triple vessel disease had, respectively, 41.5 and 63 percent 6 year mortality rates. Survival was related to the number of vessels involved. Patients with single vessel disease of the left anterior descending artery had a significant annual mortality rate. The prognosis improved when good angiographic collateralization was present, particularly in single vessel disease with total occlusion. Functional disability, classified according to the New York Heart Association criteria, was related to mortality rates and proved a useful indicator in large patient groups. Prior myocardial infarction, location of the lesion above or below the major septal perforator in left anterior descending artery disease, and left main trunk lesions did not alter the prognosis significantly.