Ventricular arrhythmias in relation to coronary artery stenosis and left ventricular performance

The relationship between ischaemic heart disease and occurrenceof ventricular arrhythmias has been studied in a prospectiveinvestigation of 41 patients with severe stable angina pectoris.The patients had a median age of 54 years (range 38–67).Following the therapeutic evaluation of the patients, they weresubjected to exercise testing, 24 h ambulatory ECG monitoring,selective coronary arteriography, ventriculography and cardiaccatheterization. Nineteen patients had been under treatmentwith a beta blocking agent, 16 with verapamil, three with bothand three had not been receiving any anti-anginal treatment.The treatment was discontinued over a period of three days priorto coronary arteriography and haemodynamic measurements. A comparisonof the patients under treatment with a beta blocking agent andthose receiving verapamil demonstrated no difference in thenon-invasive and invasive variables. Ventricular arrhythmias were found in only one patient duringexercise testing. The occurrence of ST segment deviation duringexercise was not correlated with the number of stenotic coronaryvessels due to low maximum heart rate and treatment. A heartrate during maximum exercise of < 120/min was observed significantlymore frequently in patients with multivessel disease. The data of the 24 h Holter monitoring were analysed in orderto evaluate whether the prevalence (percentage number of patientswith ventricular ectopic beats) or the persistence (number of6 h periods with ventricular ectopic beats) is the better indicatorof myocardial function and coronary artery anatomy. The resultsdemonstrated a significant correlation between a high persistenceand elevated left ventricular enddiastolic presure, high dp/dt/_max/P,reduced ejection fraction as well as the number of stenoticcoronary arteries and hypokinetic segments in the left ventricularwall. The latter correlation especially applies when the hypokinesiais localized to the anterior wall of the left ventricle. It is concluded from this investigation that a high persistenceof ventricular arrhythmias during 24 h of ECG monitoring reflectsmultivessel disease and poor left ventricular function. Thecombination of a high persistence of complicated ventriculararrhythmias and only a slight rise in heart rate during maximumexercise can possibly identify a group with an especially highrisk of sudden cardiac death.     

Upright bicycle exercise echocardiography after coronary artery bypass grafting

Upright bicycle exercise echocardiography and coronary angiography were performed in 42 patients from 1 month to 15 years (mean 6.3 years) after coronary artery bypass grafting (CABG) to determine if exercise-induced wall motion abnormalities could be correlated with the presence and location of nonrevascularized vessels. Nonrevascularized vessels were defined as obstructed vessels without grafts, obstructed grafts or native vessels obstructed distal to bypass graft insertion. Adequate quality echocardiograms were recorded at rest, peak exercise and after exercise in 38 patients (90%). Rest and postexercise echocardiograms were adequate in 3 others. Only 1 patient was excluded from analysis for inadequate peak and postexercise echocardiograms. Exercise-induced wall motion abnormalities were present in 33 of 35 patients (94%) who had 1 or more nonrevascularized vessels and these abnormalities were absent in 5 of 6 (83%) who had all vessels revascularized. Wall motion abnormalities were localized to the territory of the left anterior descending (LAD) artery or to a combined right (R) coronary-left circumflex (LC) region of circulation. Exercise-induced wall motion abnormalities were present in 24 of 27 LAD artery regions (89%) and 23 of 26 R-LC regions (88%) that had nonrevascularized vessels. These abnormalities were absent in 13 of 14 LAD regions (93%) and in 12 of 15 R-LC regions (80%) that had only revascularized vessels. Upright bicycle exercise echocardiography was successfully performed after CABG. The technique detected and accurately localized nonrevascularized and revascularized vessels.     

186例老年冠心病患者是、否体外循环下冠脉旁路移植术的比较

目的:比较老年冠心病患者体外循环与非体外循环下冠状动脉旁路移植术的疗效。方法:A组选择87例65岁以上的老年患者在体外循环下行冠状动脉旁路移植术(CCABG);B组选择79例65岁以上的老年患者在非体外循环下行冠状动脉旁路移植术(OPCABG)。结果:B组死亡率低于A组(P<0.05),术后胸腔引流量明显少于A组(P<0.05)。结论:老年冠心病患者行冠状动脉旁路移植术是安全的。     

Atenolol for the prevention of arrhythmias following coronary artery bypass grafting

Seventy patients undergoing aortocoronary bypass grafting were randomized, double-blind, to receive either atenolol or placebo. There were 35 patients in each group. Patients received either atenolol 5 mg intravenously or matching placebo within 3 h of the completion of surgery. A second intravenous dose was administered 24 h following the first and then atenolol 50 mg orally or matching placebo was given for six days. Continuous Holter monitor recordings were obtained for the 24 h immediately preoperatively and continuously for eight days postoperatively. No patient received any antiarrhythmic drug preoperatively. Patients who required pharmacological intervention for the management of postoperative arrhythmias were withdrawn as treatment failures. Holter monitor analysis continued for 24 h following withdrawal of a treatment failure. All patients were analyzed according to the intention-to-treat principle. Both groups were comparable with respect to age, sex, severity of coronary artery disease, left ventricular ejection fraction, preoperative use of beta-blockers, bypass time, aortic cross-clamp time, number of grafts per patient and frequency of preoperative arrhythmias. Arrhythmia analysis was done manually. Supraventricular arrhythmias (atrial tachycardia, atrial fibrillation and atrial flutter) were classified as either mild (less than 0.5 mins, less than 140 beats/min), moderate (0.5 to 30 mins, 140 to 180 beats/min), or severe (longer than 30 mins, more than 180 beats/min). Ventricular arrhythmia analysis was performed with respect to isolated PVCs, couplets, triplets and episodes of nonsustained ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy of flecainide acetate for atrial arrhythmias following coronary artery bypass grafting

The antiarrhythmic efficacy of intravenous flecainide and intravenous digoxin was assessed in 29 patients (26 men), aged 43 to 73 (63 +/- 7) years who developed atrial arrhythmias in the first 96 hours after coronary artery bypass grafting. Twenty-seven had atrial fibrillation and 2 had atrial flutter. Patients were entered into the study if the arrhythmia persisted for at least 15 minutes with a ventricular rate greater than 120 beats/min. Fifteen patients were randomized to flecainide (group 1) and 14 to digoxin (group 2). Flecainide was given as a bolus of 1 mg/kg over 10 minutes followed by an infusion of 1.5 mg/kg/hr for 1 hour and then 0.25 mg/kg/hr for the rest of the study period (24 hours). Digoxin was given as 3 bolus doses (0.5 mg followed after 6 and 12 hours by 0.25 mg). In both groups, 10 mg of verapamil was given intravenously after 45 minutes if the arrhythmia persisted with a mean ventricular rate greater than 100 beats/min. The antiarrhythmic efficacy was assessed by 24-hour Holter monitoring and frequent 15-second rhythm strips. Within 45 minutes control of arrhythmia, which was maintained for the rest of the study period, was achieved in 10 of 15 patients in group 1 and 2 of 14 in group 2 (p less than 0.01). Nine of 15 reverted to sinus rhythm in group 1 compared to 0 of 14 in group 2 and 1 of 15 remained in arrhythmia with a controlled ventricular rate in group 1 compared to 2 of 14 in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Long-term exercise performance after percutaneous transluminal coronary angioplasty and coronary artery bypass grafting

In our first 169 consecutive patients admitted to undergo percutaneous transluminal coronary angioplasty (PTCA) serial bicycle ergometric exercise sessions were scheduled to assess long-term-exercise performance. In 160 of these 169 patients (95%) an average of seven ergometric measurements were available during a mean follow-up period of 29 months (range 1 to 60 months). Two groups were formed. One consisted of 132 patients in whom PTCA was successful and the other consisted of 28 patients with failure of PTCA who subsequently underwent coronary artery bypass grafting (CABG) either on an emergency basis (12 patients) or as an elective procedure (16 patients). Exercise performance was expressed as work capacity in watts according to the highest completed exercise stage. In the successful PTCA group the actual work capacities increased from 74 +/- 42 W (mean +/- SD) before PTCA to 122 +/- 47 W at the most recent follow-up examination. In patients who underwent emergency or elective CABG the respective figures were 73 +/- 34 or 65 +/- 37 W before surgery and 120 +/- 41 or 119 +/- 41 W at the most recent follow-up examination (p less than .005 for all preprocedure to postprocedure comparisons). Successful PTCA and CABG after failed PTCA improve work capacity significantly. Comparison of our results with those of surgical studies indicates that a failed attempt at PTCA before CABG does not compromise the functional outcome of the operation, regardless whether it is done on an emergency or on an elective basis.     

小切口与胸骨正中切口在冠状动脉旁路移植手术中的比较

目的:比较左胸小切口冠状动脉旁路移植手术(MIDCAB)与常规正中切口冠状动脉旁路移植手术(CABG)的临床效果。方法:2012年10月至2015年12月,采用左胸小切口取左乳内动脉(LIMA)心脏不停跳CABG术45例和常规正中开胸CABG手术50例。比较术前基本情况、手术时间、出血量、术后疼痛评分、围术期心肌梗死、死亡等指标;所有患者均在术后1年时进行随访,比较术后1年的吻合口再狭窄、心绞痛、心肌梗死、脑卒中及死亡等重要终点事件发生率。结果:入选两组患者术前一般情况无显著差别。两组患者均成功施行不停跳CABG手术,围术期均无死亡。MIDCA组具有手术时间短,围术期出血少等优点。但MIDCAB组术后疼痛程度较常规正中切口CABG组大。两组在围术期心肌梗死发生、切口愈合不良发生率上差异无统计学意义。随访1年时,两组患者在心绞痛、心肌梗死、死亡、脑卒中、吻合口再狭窄等终点事件差异均无统计学意义。结论:MIDCAB术具有与传统正中切口手术一样的近中期效果,MIDCAB术安全可行,值得推广。     

Coronary artery surgery: conventional coronary artery bypass grafting versus off-pump coronary artery bypass grafting

PURPOSE OF REVIEW: Coronary revascularization has become the principal treatment modality in patients with severe coronary artery disease. The broader application of percutaneous coronary interventions in patients with multivessel disease and the recent introduction of drug-eluting stents have both lead to a decline in the number of patients referred for surgical revascularization. Conventional coronary artery bypass grafting using cardiopulmonary bypass is an excellent treatment, however less invasive surgical approaches such as off-pump coronary artery bypass grafting have appeared in the past few years. The exact role of off-pump coronary artery bypass grafting is still vaguely defined and being critically evaluated. Our aim is to provide an objective review of the recent literature in regard to surgical outcomes. RECENT FINDINGS: A critical review of all relevant clinical series from May 2003 to May 2005 was conducted. Current prospective data suggests that both techniques have similar rates of mortality, in regard to morbidity, multiple prospective studies suggest a decrease in stroke rates for off-pump coronary artery bypass grafting. The incidence of postoperative myocardial infarction does not appear to differ between techniques. When analyzed carefully, the results presented herein seem to indicate that both techniques provide similar rates for long-term patency and freedom from surgical reintervention. SUMMARY: Coronary artery bypass grafting and off-pump coronary artery bypass grafting are both safe and beneficial in patients with multivessel coronary artery disease. It appears that elderly patients with additional co-morbid risk factors may benefit most from off-pump coronary artery bypass grafting. It has become increasingly apparent that off-pump coronary artery bypass grafting can be performed safely in reference centers.     

Prevalence and prognostic significance of exercise-induced ventricular arrhythmias after coronary artery bypass grafting

Exercise-induced ventricular arrhythmias occur often after coronary artery bypass grafting (CABG), but their prognostic significance is unknown. Two hundred patients examined by exercise electrocardiography and cardiac catheterization (including left ventriculography, bypass graft and native coronary artery angiography) before and 3 months after CABG were prospectively followed up. Exercise-induced ventricular arrhythmias occurred more often after (49 of 200 patients, 24.5%) than before (32 of 200 patients, 16.0%) CABG (p less than 0.05). There were no differences between the patients with and without ventricular arrhythmias in the prevalence of graft patency (79 vs 80%) or the postoperative ejection fraction (57 +/- 9 vs 57 +/- 12%). Ten cardiac deaths occurred during the mean follow-up time of 61 +/- 19 months, 8 of which were witnessed sudden cardiac deaths. All cardiac deaths occurred in patients who did not have exercise-induced ventricular arrhythmias after CABG. The postoperative ejection fraction was lower in the cardiac death patients (42 +/- 16%) than in the survivors (58 +/- 10%) (p less than 0.01). No other clinical or angiographic variable predicted the occurrence of cardiac death. Thus, the prevalence of exercise-induced ventricular arrhythmias increases after CABG, but the occurrence of ventricular arrhythmias does not indicate an increased risk of cardiac death.     

Ventricular arrhythmias during exercise testing: mechanism, response to coronary bypass surgery and prognostic significance

To investigate the determinants and prognostic significance of ventricular arrhythmias during exercise testing, 86 patients with such arrhythmias were identified from a consecutive series of 446 patients who underwent treadmill exercise testing and cardiac catheterization. The prevalence of these arrhythmias was 19% in the total group but increased to 30% in the 120 patients with 3-vessel or left main coronary artery disease. Patients with exercise-induced arrhythmias were more likely to have 3-vessel or left main coronary artery disease, a lower resting ejection fraction, greater than or equal to 2 mm of ischemic ST depression and more severe segmental wall motion abnormalities than patients without this finding (p less than 0.05). Repeat exercise testing in 22 patients with exercise-induced arrhythmias after coronary bypass surgery revealed that persistence of these arrhythmias was associated with either severe wall motion abnormalities preoperatively or residual ischemic ST depression during the post-operative exercise testing. At a mean follow-up period of 5.3 years, the presence of exercise-induced ventricular arrhythmias was not associated with increased cardiac mortality in the medically treated patients.     

Effect of coronary artery bypass grafting on left ventricular response to isometric exercise

The left ventricular (LV) response to isometric exercise was evaluated in 20 patients who performed handgrip exercise tests before and 3 months after coronary artery bypass grafting. Preoperative LV ejection fraction (EF) decreased during the handgrip test from 0.57 +/- 0.08 to 0.49 +/- 0.09 (p less than 0.001); the ratio between the LV peak systolic pressure (PSP) and end-systolic volume index (ESVI) did not change. In 12 patients with patent grafts, the LVEF after operation did not change (0.54 +/- 0.06 at rest and 0.56 +/- 0.06 during handgrip exercise) and PSP/ESVI ratio increased from 4.5 +/- 1.5 to 5.6 +/- 2.1 mm Hg/ml X m-2 (p less than 0.001) during exercise. In 8 patients with occluded grafts, the LVEF after operation decreased from 0.56 +/- 0.10 to 0.48 +/- 0.06 (p less than 0.02), whereas PSP/ESVI did not change during handgrip exercise. Thus, the LV response to isometric handgrip exercise appears to improve after coronary artery bypass grafting in patients with patent grafts, but not in patients with 1 or more occluded grafts.     

Coronary artery bypass grafting in the management of ventricular arrhythmias in patients with coronary artery disease

This review analyzes the role of coronary artery bypass grafting in ventricular arrhythmia associated with exertion, problematic sustained ventricular tachycardia, and sudden cardiac death associated with documented ventricular arrhythmia, or first manifestation of coronary artery disease. Specifically discussed is the role of acute ischemia in initiating and perpetuating ventricular arrhythmia. Coronary artery bypass grafting is indicated as a curative intervention for ventricular arrhythmia, but in only one rare instance: exercise-induced ischemia associated with problematic sustained ventricular arrhythmia, when the tachycardia is documented as being induced by acute ischemia. In other instances, indications for coronary artery bypass grafting follow the current guidelines based on clinical trials. Patients with the most severely damaged coronary artery anatomy associated with impaired left ventricular dysfunction have their life expectancy significantly prolonged after coronary artery bypass grafting. These results have been presented as evidence that coronary artery bypass grafting prevents ventricular arrhythmia and sudden cardiac death by modifying the two most powerful predicting factors of sudden cardiac death: coronary artery anatomy and left ventricular function.     

Use of the exercise test to predict prognosis after coronary artery bypass grafting

The objective of this study was to predict the prognosis of patients who become symptomatic after having undergone coronary artery bypass grafting (CABG) using clinical and exercise test responses. A retrospective analysis was performed of all veterans referred for clinical indications to a Veterans Administration Medical Center for a treadmill test after having undergone CABG. Of 2,044 patients who were exercise tested from April 1984 to May 1987, 296 had previously undergone CABG. Clinical data considered included age, sex, medication and symptom status, history of myocardial infarction, type of myocardial infarction and time from CABG. The exercise test responses considered were MET level, maximal heart rate, maximal systolic blood pressure, chest pain pattern and ST-segment response. During a 2-year follow-up after exercise testing, there were 15 deaths, 11 nonfatal myocardial infarctions, 6 repeat CABGs and 3 percutaneous transluminal coronary angioplasties. Although MET level and maximal heart rate were significantly related to prognosis and no patient who exceeded 8 METs died, the predictive power of these exercise test responses was low and ST-segment depression was not predictive at all. The inability of the exercise electrocardiogram to predict cardiac events in patients after CABG requires the use of other methods of testing to identify those who need invasive studies and intervention.     

Concomitant aortoaxillary bypass and coronary artery bypass grafting

The optimal revascularization strategy for patients with subclavian and coronary artery disease has not been established. This study assessed the mid-term clinical outcome of concomitant aortoaxillary bypass and coronary artery bypass grafting in 5 patients. A ring-reinforced polytetrafluoroethylene graft was attached to the ascending aorta and led to the proximal segment of the axillary artery via the pleural cavity. Patients were followed up for 2-10 years (mean, 5.4 +/- 3.4 years). Postoperative aortography and angiography demonstrated patent aortoaxillary and coronary bypass grafts in the short-term follow-up of all patients. Two patients with Takayasu aortitis needed re-operations for recurrent angina and annuloaortic dilatation. Another patient required removal of the aortoaxillary bypass graft because of infection, and subsequently underwent a left femoroaxillary bypass one year after the original procedure. Subclavian steal phenomenon did not occur. Aortoaxillary bypass with coronary artery bypass may be an effective option for patients with co-existing subclavian and coronary artery disease.     

体外循环与非体外循环冠状动脉旁路移植术早期疗效分析

目的:探讨体外循环冠状动脉旁路移植术(CCABG)和非体外循环冠状动脉旁路移植术（OPCABG）早期疗效的差异。方法: 采集自2003年10月~2008年1月我院单纯冠状动脉旁路移植术5325例临床资料,分为CCABG组（343例）与OPCABG组（4 982例）。对两组患者各项术前因素、术中因素、手术死亡率及并发症进行比较。结果: OPCABG组实际手术死亡率（1.7％）明显低于CCABG组（6.7％）,P<0.01;术后二次开胸止血、肾功能不全等并发症的发生率及ICU停留时间、呼吸机辅助时间、术后住院时间都低于CCABG组（P<0.05,P<0.01）。风险调整后CCABG组手术死亡率仍高于OPCABG组6个百分点,术后并发症的发生率均略高于OPCABG组（P<0.05）。结论: CCABG与OPCABG早期临床疗效均令人满意,后者更好一些。