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Biomedical subjects

R J Capone

Publications and source records attributed to R J Capone.

At least 37 records · Page 2Linked to original sources
PubMed1988

Clinical significance and prognostic importance of left ventricular hypertrophy in non-Q-wave acute myocardial infarction.

Left ventricular (LV) hypertrophy is known to be an independent risk factor for cardiac death, but its significance in non-Q-wave acute myocardial infarction (AMI) has not been assessed previously. In a randomized diltiazem-placebo-controlled therapeutic trial of non-Q-wave AMI confirmed by creatine kinase-MB (CK-MB), 126 of 544 patients (23%) exhibited LV hypertrophy using standard voltage criteria. Compared to patients without LV hypertrophy, patients with LV hypertrophy were significantly older (65 vs 60 years, p less than 0.0001) and had smaller peak adjusted CK levels (490 +/- 376 vs 666 +/- 726 IU/liter, p less than 0.001) than patients without LV hypertrophy. Patients with and without LV hypertrophy did not differ significantly in acute mortality during hospitalization, progression to Q waves, reinfarction by CK-MB criteria or angina associated with transient electrocardiographic changes. Compared with patients without LV hypertrophy, those patients with non-Q-wave AMI and LV hypertrophy had a 2-fold higher incidence of reinfarction (24 vs 12%, p less than 0.005) and death (19 vs 9%, p = 0.044) during the first year of follow-up. Multivariate regression analysis revealed that the relative risk of death and reinfarction during the initial year after AMI was increased by a factor of 1.7 and 2.1 among patients with LV hypertrophy, respectively. It was therefore concluded that, although patients with LV hypertrophy and non-Q-wave AMI have smaller enzymatic infarcts and the same short-term prognosis as do patients without LV hypertrophy, their reinfarction and mortality rates are significantly increased during the first year of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

Psychological distress as a predictor of ventricular arrhythmias in a post-myocardial infarction population.

A prospective study examining the relationship between psychological distress and ventricular ectopy was conducted with 125 post-myocardial infarction patients equipped with a transtelephonic ECG monitor. Subjects were subsequently grouped according to the occurrence (n = 59) or nonoccurrence (n = 65) of ventricular arrhythmias over a 1-year period. Results indicated a direct relationship between self-reported distress levels and occurrence of ectopic beats. This relationship was unaltered by adjusting simultaneously for known predictors of arrhythmias, including cardiac risk, age, and the prescription of beta-blocker agents. Thus this study represents an initial demonstration in a post-myocardial infarction population that psychosocial factors have prognostic significance for arrhythmias and, presumably, sudden death.

Arrhythmias, Cardiac↗
PubMed1988

The effects of a transtelephonic surveillance and prehospital emergency intervention system on the 1-year course following acute myocardial infarction.

We evaluated the effect on morbidity and mortality of a post-myocardial infarction management and intervention system. One thousand four patients were prospectively randomized to an intervention group that included routine and emergency transtelephonic follow-up and ECG monitoring or to control; all subjects were followed for 1 year. For symptoms suggestive of myocardial ischemia, intervention patients telephoned the project emergency office, were instructed by a project nurse to self-administer intramuscular lidocaine with an auto-injector, and were then transported to the nearest emergency facility. Cardiac death or arrest was decreased 29% in intervention patients (p = 0.066), while all-cause mortality was decreased by 24% (p less than 0.11). Routine transtelephonic ECG monitoring detected ventricular ectopy in 48% of intervention patients, with almost 50% of these findings classified as complex forms. Ventricular ectopy detected during routine calls within 60 days of the acute myocardial infarction conferred a threefold increase in mortality (p = 0.001). In addition, control patients were 2.4 times more likely to be clinically depressed (p less than 0.03) and returned to work less quickly (p less than 0.03) when compared to intervention patients. Lidocaine injections were associated with an absence of ventricular ectopy on arrival at the Emergency Room in 64% and with a low incidence of lidocaine-associated side effects. There was only one case of unauthorized use of the self-injector. These findings demonstrate that an outpatient post-myocardial infarction transtelephonic surveillance program can be safely and effectively conducted, can detect complex ventricular arrhythmias of prognostic significance, can improve the quality of life, and may reduce 1-year cardiac mortality.

Clinical Trials as Topic↗
PubMed1988

Quality of life post-myocardial infarction: effects of a transtelephonic coronary intervention system.

The impact of an outpatient, risk-management system, including a transtelephonic electrocardiographic monitor and lidocaine injector, on the quality of life in post-myocardial infarction patients was examined. Patients (n = 238) were assigned randomly to either the system or to standard medical care (control). Quality of life was defined in terms of psychological status, return to work, and social functioning. Relative to control patients, system patients showed a significant decrease in concerns about physical functioning and symptoms, and, over time, reported less depressive affect. At 9-month follow-up, control patients were more than twice as likely to be in the range of clinical depression. Patients' perceptions of their ability to manage a recurrence of cardiac symptoms appeared to be related inversely to depressive affect. Moreover, a larger percentage of system patients (92%) had returned to work by the 9-month follow-up, compared with control patients (76%). There were, however, no significant differences between groups in the degree of impairment in social interaction. Overall, these results indicate that the use of a "system" encouraging patient participation in treatment can significantly improve qualify of life after a myocardial infarction.

Depression↗
PubMed1988

Effect of pressure-controlled intermittent coronary sinus occlusion on pacing-induced myocardial ischemia in domestic swine.

This study tested the hypothesis that pressure-controlled intermittent coronary sinus occlusion (PICSO) would be useful in ameliorating myocardial ischemia under conditions characterized by preserved, but reduced (relative to demand), myocardial blood flow. Studies were conducted in closed-chest, sedated domestic swine prepared with an artificial stenosis that reduced luminal diameter of the animal's left anterior descending coronary artery by 80%. Measurements of hemodynamics, regional myocardial blood flow, and oxygen, lactate, and nucleoside metabolism were obtained in 10 animals (1) before placement of stenosis, (2) 30 min after insertion of stenosis, (3) after 30 and 60 min of PICSO, and (4) 30 min after discontinuation of PICSO. Two groups of control animals were studied to observe the natural history of metabolic markers of ischemia. Control group I consisted of four animals studied concurrently and subjected to the same protocol except for the fact that PICSO was not applied. Control group II consisted of eight additional animals studied as a group. A specially designed balloon-tipped catheter positioned in the proximal portion of the animal's great cardiac vein was used to provide PICSO. Heart rate was controlled by atrial pacing (rate, 145 beats/min) through the study. After placement of the stenosis, flow in endocardial and transmural layers distal to the stenosis declined significantly (p less than .01) vs control. Application of PICSO failed to increase arterial inflow distal to the stenosis in any myocardial layer. Myocardial aerobic metabolism was adversely affected by stenosis and changed from consumption of lactate, inosine, and hypoxanthine before stenosis to production at 30 min after stenosis. Although PICSO was associated with reduced production and a return toward consumption of lactate, inosine, and hypoxanthine, a similar pattern of changes in lactate, inosine, and hypoxanthine metabolism was observed in control animals over a comparable period of time. In addition, regional myocardial oxygen extraction and consumption were not changed vs poststenosis levels by PICSO. However, in comparison with controls, PICSO did accelerate the rate of resolution of myocardial ischemia as assessed by lactate metabolism. At 30 min of PICSO (or sham) the change vs poststenosis was +33.6 +/- 25.0 mumol/min/100 g in the PICSO but only +6.7 +/- 29.7 in the control group (p = .05). We conclude, therefore, that even though PICSO did not alter the final level of myocardial ischemia under conditions modeled in this study it did accelerate its rate of resolution, an effect that may be beneficial clinically.

Animals↗
PubMed1988

Metabolic response to prolonged reduction of myocardial blood flow distal to a severe coronary artery stenosis.

Limited data are available concerning the effects of mild-to-moderate, sustained reductions of coronary blood flow on myocardial aerobic metabolism. This study tested the hypothesis that a sustained flow reduction distal to a severe coronary artery stenosis may be well tolerated (after the initial insult is passed) because of gradual improvement in the balance between myocardial oxygen supply and demand. Studies were performed in eight sedated, closed-chest domestic swine that were instrumented with an artificial coronary arterial stenosis (80% diameter reduction). Hemodynamics, regional myocardial blood flow and oxygen, lactate, acid, and base metabolism were measured before stenosis and at 5, 20, 60, 120, and 180 minutes after stenosis insertion. Regional myocardial function (ultrasonic length sensors) was measured serially during 2 hours in three additional swine. After stenosis placement, endocardial and transmural flows declined (p less than 0.05) compared with flows before stenosis (from 1.54 +/- 0.37 to 0.73 +/- 0.24 ml/min/g [mean +/- SD] and from 1.44 +/- 0.31 to 1.19 +/- 0.25 ml/min/g, respectively). Thereafter, flows remained unchanged for the duration of the study. Similarly, prestenosis heart rate (135 +/- 7 beats/min), aortic mean pressure (113 +/- 17 mm Hg), and tension time index (27.1 +/- 3.6 mm Hg.sec) remained constant for the duration of the study. In contrast, regional coronary venous pH declined (p less than 0.05) compared with prestenosis levels (7.35 +/- 0.02) 5 minutes after stenosis (7.28 +/- 0.04), but it returned to prestenosis levels during the next hour. Regional coronary venous PCO2 exhibited a similar pattern (i.e., acute increase during poststenosis with gradual return to prestenosis levels).(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1987

Electrocardiographic evolution of posterior acute myocardial infarction: importance of early precordial ST-segment depression.

Precordial ST-segment depression is typically observed in anterior non-Q-wave acute myocardial infarction (AMI), and is generally not regarded as an indication for acute thrombolytic therapy. Of 544 patients with creatine kinase (CK)-MB-confirmed non-Q-wave AMI randomized to the prospective multicenter Diltiazem Reinfarction Study, 50 patients (9.2%) had isolated precordial ST-segment depression of 1 mm or more in 2 or more contiguous precordial electrocardiographic leads (V1-V4). Serial electrocardiograms recorded at study entry (mean 50.5 hours after onset of chest pain), on study day 2, study day 3 and at predischarge showed that in 23 of 50 patients (40%) electrocardiographic evidence of posterior AMI evolved, defined as an R wave of 0.04 second or more in lead V1 and an R:S greater than or equal to 1 in lead V2. In 18 of these 23 patients (78%), posterior AMI had evolved by study day 3, and none had an abnormal reelevation of CK-MB (every 12-hour sampling) for up to 14 days of hospitalization. Compared with the remaining 27 patients who had electrocardiographic features of anterior non-Q-wave AMI only, the 23 with initial precordial ST segment depression in whom posterior AMI developed had significantly higher mean peak CK values (1,051 +/- 172 vs 663 +/- 89 IU, p less than 0.009) and greater mean precordial ST-segment depression in lead V1 (0.28 vs + 0.19 mm, p = 0.01), in lead V2 (1.3 vs 0.26 mm, p = 0.003) and in lead V3 (2.0 vs 0.93 mm, p = 0.0004).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗
PubMed1987

A paucity of thalassemia trait in Italian men with myocardial infarction.

We studied the prevalence of thalassemia trait in a group of Italian male myocardial infarction (MI) patients and an ethnically similar group of men admitted for other conditions. Italian men constituted approximately 13% of each group. Of 359 Italian men with a MI, only 2 had thalassemia trait. In contrast, of 330 adult Italian males in the non-MI group (mean age 59.6 years), 11 had thalassemia trait. Because the frequency of thalassemia trait was significantly (p less than 0.01) lower in the myocardial infarct group, we conclude that thalassemia trait may be a protective attribute as regards MI. A prospective study of individuals with thalassemia minor is indicated to elucidate the mechanism for the observed protective effect and to determine what risk factors may offset the protective effect in those that do experience MI.

Heterozygote↗
PubMed1986

Diltiazem and reinfarction in patients with non-Q-wave myocardial infarction. Results of a double-blind, randomized, multicenter trial.

We performed a multicenter, double-blind, randomized study to evaluate the effect of diltiazem on reinfarction after a non-Q-wave myocardial infarction. Nine centers enrolled 576 patients: 287 received diltiazem (90 mg every six hours) and 289 received placebo. Treatment was initiated 24 to 72 hours after the onset of infarction and continued for up to 14 days. The primary end point, reinfarction, was defined as an abnormal reelevation of MB creatine kinase in plasma within 14 days. Reinfarction occurred in 27 patients in the placebo group (9.3 percent) and in 15 in the diltiazem group (5.2 percent)--a 51.2 percent reduction in cumulative life-table incidence (P = 0.0297; 90 percent confidence interval, 7 to 67 percent). Diltiazem reduced the frequency of refractory postinfarction angina (a secondary end point) by 49.7 percent (P = 0.0345; 90 percent confidence interval, 6 to 73 percent). Mortality was similar in the two groups (3.1 and 3.8 percent, respectively, in the placebo and diltiazem groups), but adverse drug reactions (most of which were mild) were more common in the diltiazem group. Nevertheless, the drug was well tolerated, despite concurrent treatment with beta-blockers in 61 percent of the patients. We conclude that diltiazem was effective in preventing early reinfarction and severe angina after non-Q-wave infarction and that it was also safe and generally well tolerated.

Aged↗
PubMed1986

Effect of propranolol in patients with myocardial infarction and ventricular arrhythmia.

The Beta-Blocker Heart Attack Trial was a placebo-controlled, randomized, double-blind clinical trial of the long-term administration of propranolol hydrochloride to patients who had had at least one myocardial infarction. Among 3,837 patients followed up for an average of 25 months, 3,290 (85.7%) had 24 hour ambulatory electrocardiograms performed at the baseline examination. Four classifications of arrhythmia were examined. One of these, the presence of complex ventricular arrhythmias (at least 10 ventricular premature beats/h, or at least one pair or run of ventricular premature beats or multiform ventricular premature beats) was the subgroup of major interest. Regardless of the classification, the presence of arrhythmia identifies a group of patients with a higher risk of total mortality, coronary heart disease mortality, sudden cardiac death and instantaneous cardiac death. The a priori subgroup hypothesis that sudden death would be preferentially reduced by propranolol in patients with complex ventricular arrhythmias was not supported. The relative benefit of propranolol in reducing sudden death for this subgroup was 28 versus 16% for the subgroup without ventricular arrhythmia (relative risk of 0.72 versus 0.84, a nonsignificant relative difference of 14%). There were similar findings for two of the three other classifications of arrhythmia and for the other response variables. Although propranolol does not appear to be of special relative benefit in patients with ventricular arrhythmia, the presence of the arrhythmia does identify a high-risk group. The mechanism by which propranolol reduces mortality is still unclear, but is probably not solely an antiarrhythmic one.

Adult↗
PubMed1985

Cardiac complications following tricyclic antidepressant overdose. Issues for monitoring policy.

Thousands of people in the United States poison themselves with tricyclic antidepressants each year. While these patients often require cardiac monitoring for potential arrhythmias, clinical practice is highly variable in regard to the hours of monitoring required. Clarification of this issue is important because of the impact on resources. This study retrospectively reviews the monitoring practices and cardiac complications following tricyclic antidepressant overdose in 75 adults. The patients received an average of 61.7 hours of monitoring. The vast majority of electrocardiographic changes, including three cardiac arrests, appeared within the first 24 hours. No patient with a normal level of consciousness and a normal electrocardiogram for 24 hours went on to develop any significant arrhythmia. On the basis of these data and an extensive literature review, we propose that current guidelines for cardiac monitoring following tricyclic antidepressant overdose be reconsidered.

Adolescent↗
PubMed1984

The effect of early prehospital transtelephonic coronary intervention on morbidity and mortality: experience with 284 postmyocardial infarction patients in a pilot program.

We have evaluated, in a pilot study, the effects of subsequent mortality and morbidity of a prehospital program for postmyocardial infarction patients experiencing recurrent chest pain. Two hundred eighty-four patients were enrolled during their late hospital period: 161 in a program incorporating patient education, routine transtelephonic follow-up, and emergency prehospital CCU-controlled intervention; 124 in a control group receiving usual medical care. Cardiac mortality over a median of 13 months of follow-up was significantly reduced in the treatment group (5.8%) vs control (12.9%), p = 0.036, although the incidence of acute events (nonfatal infarction plus cardiac death) was similar in both groups. This suggests that the program does not affect the acute incident but rather the mortality subsequent to it. Prehospital ventricular arrhythmias present in 7 of 54 treatment patients with recurrent chest pain did not recur following self-injection by a prefilled lidocaine syringe; only one patient who was initially arrhythmia-free had ventricular ectopic beats after lidocaine injection. Delay from onset of symptoms to hospital arrival was 1.9 hours. Routine telephone follow-up uncovered ventricular arrhythmias in 30% of treatment patients and, despite the program's patient educational efforts, unreported angina in 20% of the treatment group. In the treatment group there were 99 emergency calls placed by 62 patients, 50% within 12 weeks after discharge and 80% by 35 weeks, resulting in 74 Emergency Department evaluations and 57 hospital admissions. Overuse of the emergency system occurred with only one patient, and physician acceptance was high.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1983

Effects of propranolol on blood lipids and lipoproteins in myocardial infarction.

The effects of propranolol on lipids and lipoproteins were investigated in survivors of a recent myocardial infarction who were enrolled in the double-blind Beta-Blocker Heart Attack Trial. Nonfasting serum samples were obtained in more than 2800 patients assigned randomly to either propranolol or placebo. The propranolol-treated group had high-density lipoprotein cholesterol levels 3-4 mg/dl less and triglyceride concentrations 30-40 mg/dl higher than the placebo group. These effects occurred in men and women in all age categories.

Adult↗
PubMed1983

Long-term changes in canine vein graft after infusion of cardioplegic solution.

We have studied the effects of cardioplegic solution (CS) on angiographic and histologic anatomy of bilateral vein grafts interposed into the carotid arteries of 10 dogs for up to 1 year. One vein (exp) was infused with cardioplegic solution (pH 7.7, K + 25 mEq/l, temperature 12 degrees C) every 15 min four times at pressures up to 80 mm and then interposed into the carotid system. The other vein (con) was kept in cold Ringer's lactate (12 degrees C) before interposition. Six weeks and up to 1 year after bypass, angiograms showed 80% graft patency of exp and con grafts. Immediate histologic examination showed no detectable differences among veins before and after perfusion and con veins. Histologic examination at 1 year showed enlargement of the grafts, smooth muscle hyperplasia, and increase in collagen, as well as disorientation of muscle fibers; cytoplasmic vacuolation occurred with equal frequency in both exp and con veins. Perfusion of the vein segment with cardioplegic solution did not appear to be detrimental to vein patency or histologic appearance so that this can be considered a safe method for delivery of cardioplegia in jeopardized ischemic myocardium at the time of bypass surgery.

Animals↗
PubMed1979

The single precordial lead for ST segment monitoring: comparison with the multiple lead map.

ST segment elevation, used as an index of the relative extent of myocardial ischemic injury, was measured using a single precordial lead located at the point of maximum ST elevation. ST changes were followed for two hours after acute coronary occlusion in pigs, and were compared to the sum of ST elevation recorded with an 18 lead precordial map. Some animals were subjected to Reperfusion (n = 12), others to infarct extension (n = 10), while a control group (n = 9) was followed without an ST-modifying intervention. Correlation between sigmaST and ST in the single lead was good, with a correlation coefficient of 0.844 at 360 points of comparison. Time to peak ST elevation using the single lead technique was comparable to that using the 18 lead map. Changes in the ST elevation using both techniques were similarly reduced following reperfusion, increased following extension, and followed a similar downslope pattern in the unmodified infarct group. This single lead technique offers the advantage of simplicity of use without sacrifice of accuracy. Its use can facilitate clinical studies of myocardial ischemic injury and its modification.

Animals↗