Reperfusion of Infarct Related Artery Achieved by Direct Percutaneous Transluminal Coronary Angioplasty Counteracts Left Ventricular Remodeling after Acute Myocardial Infarction More Than Thrombolysis

The purpose of this study was to compare the effect of direct percutaneous transluminal coronary angioplasty (PTCA) and intravenous recombinant tissue plasminogen activator (rt-PA) on left ventricular remodeling in patients with acute myocardial infarction (AMI). To address this issue, patients with AMI randomly assigned to direct PTCA or intravenous rt-PA as part of a large multicenter study (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries [GUSTO] IIb Angioplasty Substudy) were evaluated with two-dimensional echocardiography at predischarge. An echocardiographic infarct size index and the end-diastolic and end-systolic left ventricular volumes were computed. Patients with an infarct size index equal to or higher than the mean value were considered to have a large infarction. Of 26 enrolled patients, 13 were assigned to PTCA (9 successfully reperfused: i.e., TIMI-3 flow after PTCA) and 13 to rt-PA (10 successfully reperfused: i.e., ST resolution after rt-PA). In patients considered successfully reperfused, end-systolic volumes tended to be lower in PTCA patients than in rt-PA patients (43 ± 17 cc vs 59 ± 21 cc, P = 0.09), although there were no differences in infarct size index (7.3 ± 2.8 vs 7.0 ± 2.8) and ejection fraction (52%± 10% vs 46%± 12%). End-systolic volume depended on infarct size index in the overall patient population (r = 0.60, P = 0.007) and in rt-PA patients (r = 0.80, P =0.005), while no correlation was found in PTCA patients. Considering patients with large AMIs, end-systolic volumes were higher in the four patients treated with rt-PA than in the four patients treated with direct PTCA (P < 0.01). Considering all the 26 enrolled patients, these differences were also present, but they did not reach statistical significance. In conclusion, our results suggest that, in patients with large AMIs, adequate reperfusion obtained by direct PTCA has a more marked effect in counteracting ventricular remodeling than that obtained by systemic rt-PA. This beneficial effect of direct PTCA, independent of any reduction in regional wall-motion abnormalities, should be taken into account when comparing the clinical value of direct PTCA with that of systemic thrornbolysis in the treatment of AMI.     

Left ventricular function in men and women. Another difference between sexes

In a group of 70 patients, 29 women and 41 men, with atypicalchest pain and normal findings at coronary arteriography, somehemodynamic and angiographic parameters of left ventricularfunction were measured, for the purpose of determining the valuesof normality and to document possible differences between sexes. Of the diastolic parameters, the left ventricular end-diastolicpressure and volume was lower in women than in men, the LVEDPbeing 11.9 ± 3.4 against 13.7 ± 3.6 mm Hg (P <0.025), and ED V of 76.1 ± 15 against 89.5 ± 23ml/m² (P < 0.005). Of the systolic parameters, the ejection fraction of 74 ±7% in women was significantly higher than that of 67 ±7% in men (P < 0.0005), and so was the mean velocity of volumereduction of 2.59 ± 0.58 of women against that of 2.26± 0.35 of men (P < 0.01). The physiological diversity between the sexes, with women showinga constant hyperdynamic condition in comparison to men, withsmaller ventricular volumes and increased contraction, seemsto offer a possible explanation for some intriguing aspectsof the diagnosis of ischemic heart disease in the female sex.     

Outpatient Electrical Cardioversion of Atrial Fibrillation: 8 Years' Experience. Analysis of Shock-Related Arrhythmias

Background: Outpatient electrical cardioversion (EC) of atrial fibrillation is currently the standard of care. Shock-related arrhythmias may be particularly deleterious in this setting. Preoperative identification of high-risk patients may be very useful.
Methods: A retrospective analysis was made of 543 consecutive elective EC procedures in 457 outpatients over an 8-year period in a university cardiological institute. The protocol included adequate anticoagulation, intravenous anesthesia, direct current shock, and a direct observation after a shock to detect procedure-related complications. No patients were excluded due to severity of pathology or comorbidities. Clinical characteristics, energy delivered, medications, arrhythmic phenomena, and predictors of success and complications were analyzed.
Results: Of 543 ECs performed, 88.2% restored sinus rhythm, which persisted at discharge in 83.2%. No anesthesia-related complications were detected. No thromboembolic complications were detected. Use of a biphasic cardioverter was the only predictor of success (P = 0.0001). The bradyarrhythmic complication rate was 1.5%. No ventricular arrhythmic events were detected. Atrial flutter was present in five of eight patients who developed complications versus 44 of 535 patients who had no complications (P < 0.0005), and prosthetic heart valves in four of eight complicated versus 40 of 535 uncomplicated cases (P = 0.0044). The combination of atrial flutter and prosthetic heart valve was found in four of eight complicated versus 11 of 535 uncomplicated cases (P < 0.0005).
Conclusion: Shock-related arrhythmias are essentially bradyarrhythmias. Atrial flutter and previous cardiac surgery identify a subgroup of patients at high risk of postshock bradyarrhythmic complications.