Oral amiodarone reduces incidence of postoperative atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a common occurrence after heart operations that use cardiopulmonary bypass. It can cause life-threatening complications as well as delay discharge and increase hospitalization costs. The purpose of this study was to evaluate the effect of orally administered low-dose amiodarone on the incidence of new onset postoperative AF. METHODS: In this prospective study, 226 consecutive adult patients (group A) who had various heart operations utilizing cardiopulmonary bypass between April and November of 1998 at the University of Miami/Jackson Memorial Hospital, were given oral amiodarone (200 mg three times a day), starting immediately after arrival in the intensive care unit until the day of hospital discharge. The incidence of new AF in this group of patients was assessed and compared with a historical group of 239 patients (group B) who had had cardiac operations with cardiopulmonary bypass in the preceding 9 months at the same institution. RESULTS: Preoperative patient characteristics and procedure types were similar in the two groups. Among the 226 patients in group A, 13 (5.7%) had history of AF. Of the remaining 213 patients, new-onset AF occurred postoperatively in 10 (4.7%). Among the 239 patients in group B, 16 (6.7%) had history of AF. Of the remaining 223 patients, 44 (19.7%) developed new-onset AF (p < 0.001). Group A patients had a shorter length of hospital stay than those in group B (6.5 versus 7.8 days) but had a similar incidence of complications other than AF (23 of 226 patients in group A versus 24 of 239 in group B). The drug was well tolerated. CONCLUSIONS: Postoperative low-dose amiodarone given orally to patients who had cardiopulmonary bypass was well tolerated and appeared to reduce the incidence of new-onset AF and decrease the length of hospital stay.

Acute results, complications, and effect of lesion characteristics on outcome with the solid-state, pulsed-wave, mid-infrared laser angioplasty system: final multicenter registry report. Holmium:YAG Laser Multicenter Investigators.

BACKGROUND AND OBJECTIVE: The solid-state, mid-infrared holmium:YAG laser (2.1 microm wavelength) is a relatively new percutaneous device that has recently been evaluated in a multicenter study. Because of its unique wavelength and photoacoustic effects on atherosclerotic plaques, this laser may be useful in treatment of symptomatic patients with coronary artery disease. This study sought to evaluate the safety and efficacy of mid-infrared laser angioplasty in the treatment of coronary artery lesions. PATIENTS AND METHODS: Laser angioplasty was performed on 2,038 atherosclerotic lesions in 1,862 consecutive patients with a mean age of 61 +/- 11 years. Clinical indications included unstable angina (69%), stable angina (20%), acute infarction (6%), and positive exercise test (5%). Complex lesion morphology included eccentricity (62%), thrombus (30%), total occlusion (27%), long lesions (14%), and saphenous vein grafts (11%). RESULTS: This laser catheter alone successfully reduced stenosis (>20%) in 87% of lesions. With adjunct balloon angioplasty, 93% procedural success was achieved. The presence of thrombus within the target lesion was a predictor of procedural success (OR = 2.0 [95% confidence interval 2.0, 4.0], P = .04). Bifurcation lesions (OR = 0.5 [95% confidence interval 0.2, 1.0], P = .05) and severe tortuosity of the treated vessel (OR = 0.4 [95% confidence interval 0.2, 0.9], P = .02) were identified as significant predictors of decreased laser success. Calcium within the lesion was associated with reduced procedural success (OR = 0.57 [95% confidence interval 0.34, 0.97], P = .03), and calcified lesions required significantly more energy pulses than noncalcified lesions (119 +/- 91 pulses vs. 101 +/- 86 pulses, respectively, P = .0002). Complications included in-hospital bypass surgery 2.5%, Q-wave myocardial infarction 1.2%, and death 0.8%. Perforation occurred in 2.2% of patients; major dissection in 5.8% of patients, and spasm in 12% of patients. No predictor of major complications was identified. Six-month angiographic restenosis was documented in 54% of patients, and clinical restenosis occurred in 34% of patients. CONCLUSION: Mid-infrared laser has a safety profile similar to that of other debulking devices. This laser may be useful in select patients presenting with acute ischemic syndromes associated with intracoronary thrombus; however, like other coronary lasers, it is limited by the need for adjunctive balloon angioplasty and/or stenting to achieve adequate final luminal diameter. No beneficial effects on reducing 6-month restenosis rates were observed.

Acute right ventricular infarction mimicking extensive anterolateral wall injury.

A patient presented with an acute right ventricular infarction characterized by an electrocardiographic current of injury in both the inferior (2,3,aVF) and anterior precordial leads (V1-V6). Cardiac catheterization demonstrated normal left ventricular wall motion, a codominant circulation, and severe disease of the right coronary artery. We propose that this coronary anatomy explains the injury currents on the electrocardiogram. This case illustrates a rare presentation of right ventricular myocardial infarction mimicking an extensive anterolateral wall injury.

Long-term surgical results in sudden death syndrome associated with cardiac dysfunction after myocardial infarction.

To evaluate the surgical results in patients with inducible ventricular tachyarrhythmias due to coronary disease and left ventricular dysfunction, the authors reviewed their experience in 170 patients who had survived one or more cardiac arrests after myocardial infarction and were unresponsive to drug therapy based on electrophysiologic studies (EPS). There were nine operative deaths (5%). Based on intraoperative EPS, surgical remodeling of left ventricular dysfunction (aneurysm resection, infarct debulking, and septal reinforcement) with map-guided cryoablation and coronary artery bypass graft was performed in 34 patients (group A), and left ventricular remodeling and coronary artery bypass graft without guided endocardial resection was performed in 25 patients (group B). Forty-three patients (group C) had coronary artery bypass graft with implantation of an automatic implantable cardioverter defibrillator (AICD). Group D (68 patients) received AICD only. After operation, based on EPS results, four patients in group A (12%) and three patients in Group B (15%) required AICD implantation. Overall survival at 6 years was 65%, 48%, 85%, and 58% in patient groups A, B, C, and D, respectively (p = not significant). During follow-up in group A patients, none died suddenly and none needed AICD. In group B, two patients required AICD 3 and 5 years later, and five patients died suddenly. The incidence of sudden death was 2.3%/patient/year and 3.5%/patient/year after AICD implantation (groups C and D). At 6 years, cardiac-event-free survival was 80% and 70% for groups A and B and 38% and 24% for groups C and D, respectively (p less than 0.001). Patients receiving map-guided ablative procedures had significantly improved cardiac-event-free survival rates.

Life-threatening ventricular arrhythmias in patients with silent myocardial ischemia due to coronary-artery spasm.

BACKGROUND: Silent myocardial ischemia in patients with coronary atherosclerosis is associated with an increased risk of adverse cardiac events, including sudden death. The relation between silent ischemia and the initiation of potentially fatal ventricular arrhythmias has not been defined, however. METHODS: As part of a long-term study of sudden cardiac death, data on arrhythmias, coronary anatomy, and responses to ergonovine testing to provoke coronary-artery spasm were collected prospectively among survivors of out-of-hospital cardiac arrest who had no flow-limiting coronary-artery lesions, prior myocardial infarctions, or other structural causes of cardiac arrest and no angina pectoris. Associations between silent myocardial ischemia due to coronary-artery spasm and the occurrence and characteristics of life-threatening ventricular arrhythmias were studied by both invasive and noninvasive techniques. RESULTS: Silent ischemic events were associated with the initiation of life-threatening ventricular arrhythmias in five patients with induced or spontaneous focal coronary-artery spasm (or both). These patients were identified among a group of 356 survivors of out-of-hospital cardiac arrest who were evaluated between 1980 and 1991. In two of the five patients reperfusion, rather than ischemia itself, correlated with the onset of the ventricular arrhythmia. Only one of the five had an inducible arrhythmia during electrophysiologic testing. Titration of the dose of a calcium-entry-blocking agent (verapamil, diltiazem, or nifedipine) against the ability of ergonovine to provoke spasm was successful in preventing both the provocation of spasm and arrhythmias in all four patients who were tested. CONCLUSIONS: Silent myocardial ischemia due to coronary-artery spasm can initiate potentially fatal arrhythmias in patients without flow-limiting structural coronary-artery lesions. The role of silent ischemia, reperfusion, or both in the initiation of fatal arrhythmias in larger groups of patients with advanced coronary-artery lesions remains to be defined.

Anomalous coronary arteries: angiographic findings in 80 patients.

Among 13010 adults who underwent coronary arteriography, 80 (0.61%) patients had a total of 83 anomalous coronary arteries. Thirty-three (41%) of the patients were of Hispanic origin, while out of the entire population studied 30% were Hispanic. The right coronary artery was the most common anomalous vessel. It was identified in 50 (62%) patients, arising in 35 from the left aortic sinus, in 14 from the posterior sinus, and in 1 from the left coronary artery. An anomalous circumflex artery was recognized in 22 (27%) patients. Nine (11%) patients presented an anomalous left anterior descending artery, 1 patient an anomalous left main coronary artery, and another an anomalous septal perforator artery. Twenty-three (29%) patients had concomitant congenital heart abnormalities, most commonly. bicuspid aortic valve and mitral valve prolapse. In each of 5 patients with complex congenital heart disease the course of the anomalous vessel could have interfered with a surgical procedure. In 4 cases anomalous coronary arteries were associated with either anomalous systemic venous circulation or anomalous cardiac veins. In 5 (6%) patients only, the anomalous coronary artery was solely responsible for a clinical event. Coronary atherosclerosis of the anomalous arteries was found in 28% of the patients, while the overall incidence of the disease in this series was 65%. Thus, anomalous coronary arteries are associated with a high incidence of congenital heart diseases, but do not appear to be associated with an increased risk for development of coronary atherosclerosis. The angiographic recognition of these vessels is important in patients who undergo coronary angioplasty or cardiac surgery. Variations in the frequency of congenital coronary anomalies as reported herein may be attributed to a genetic background.

Correlates of atherosclerosis in coronary arteries of patients undergoing angiographic evaluation.

The correlations between lipid and lipoprotein measurements and other risk factors of coronary artery disease were evaluated in 101 men undergoing coronary angiography. Clinically significant disease was present in 75 patients, whereas 24 had no observable lesions and 2 had minimal lesions. Comparisons of individual lipid and lipoprotein levels were nearly all significantly different between patients with and patients without clinically significant disease; however, no single variable could predict the presence of disease among patients. Logistic regression analysis identified five factors: apolipoprotein A-I, apolipoprotein B, diabetes, age, and family history of heart disease, which account for most of the differences between the two patient groups. These results could have important implications for the evaluation and management of patients suspected of having coronary atherosclerosis.

Pharmacologic approaches to management of arrhythmias in patients with cardiomyopathy and heart failure.

Interactions between disordered cardiac rhythm and abnormal cardiac hemodynamic function are well recognized. Demonstrations of this relationship include the relationship between prognostic significance of ventricular ectopy and left ventricular ejection fraction, impairment of ventricular function in association with loss of atrial systole in disease states, increased risk of potentially lethal arrhythmias in the myopathic ventricle, and the evolution of advanced grades of ventricular arrhythmias in acute heart failure. With the development of newer and more potent antiarrhythmic agents, in conjunction with drugs that can improve the failing circulation, it is now possible to clarify these interrelationships and perhaps develop new strategies for clinical management.