The atherosclerotic plaque.

Atherosclerosis is the most frequent cause of ischemic heart disease and cerebrovascular disorders. The condition is the leading cause of death in Western societies. At the core of this condition is the atherosclerotic plaque. It is within the structure of this lesion that multiple biochemical and cellular processes interact influencing its vulnerability to rupture and as a result acute ischemic events. This article will discuss the pathophysiology behind the atherosclerotic plaque, particularly those elements that lead to its instability and the medical tools currently available to counteract it.

Coronary artery abnormalities in Puerto Rico

A retrospective study was done to determine the frequency of coronary artery anomalies in terms of their origin, course, and structure. The clinical history, catheterization data and surgical reports of patients undergoing coronary angiography at the Cardiovascular Center of Puerto Rico and the Caribbean, from 1999 to 2004, were analyzed. Thirty-eight patients were identified with a coronary artery anomaly in this population. These anomalies were classified according to their clinical consequences and the need for surgical intervention.

Heart transplantation in females: the experience in Puerto Rico

BACKGROUND: Heart transplantation is the procedure of choice for a selected group of patients with end stage heart disease. Gender related differences have been observed in the heart transplant field: less women than men are recipients of heart transplants, more risk of rejection in female recipients, and a perception toward reduced survival in women. We report our experience of heart transplantation in females in Puerto Rico. METHODS: We studied the data bank of 69 heart transplant recipients in the Puerto Rico Heart Transplant Program from June 1999 to June 2005. Gender related differences in the number of recipients: males or females, incidence of rejection, survival, and other outcomes were analyzed. RESULTS: 69 patients received an orthotopic heart transplant from June 1999 to June 2005, in a single center in Puerto Rico. The mean age of the patients was 47 (11-62) years. Fifty patients (72%) were men, and 19 patients (28%), were women. Survival in the female group at 3 months, 1, 2, 3, 4, and 5 years was 100%, 100%, 100%, 100%, 90%, and 90% respectively. The survival in the male group at 3 months, 1, 2, 3, 4 and 5 years was 97%, 97%, 97%, 94%, 86 and 79% respectively. There was an early, higher incidence of rejection in women during the first three months post transplant; 1.5 vs. 0.75, (P=0.04) episodes per patient in the female, and male group respectively. After the third month post transplant there was no significant difference in rejection incidence. The incidence of infectious episodes was significantly more frequent in female than in male recipients, 2.8 vs. 1 (P=0.02) per patient respectively. CONCLUSIONS: There were more male than female heart transplant recipients at a ratio of 3:1, without a significant gender difference in survival. The risk of rejection was higher in females in the early period post transplantation, but thereafter this risk showed no signinificant statistical difference. The incidence of infection was more frequent in female...

[Total plasma homocysteine concentrations in Puerto Rican patients with ischemic heart disease]. / Concentraciones totales de homocisteína plasmática en pacientes puertorriqueños con cardiopatía isquémica.

INTRODUCTION AND OBJECTIVES: In Puerto Rico, it has been established that although coronary disease is the leading cause of death, the population has a lower incidence of coronary disease than in the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. One factor that could contribute to the lower incidence of coronary disease in Puerto Rico is that our population might have lower total plasma homocysteine concentrations (tHcys) than in the continental United States. Our main objective was to measure tHCys in the Puerto Rican population with atherosclerotic cardiovascular disease (ACD). METHODS: We randomly measured tHcys concentrations in seventy Puerto Rican patients who were hospitalized at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division). RESULTS: The mean tHCys concentration in these patients is similar to those reported for the Framingham study when adjusted by age (11.2 vs. 11.8 micromol/l). In the Puerto Rican population, males had a higher tHcys concentration than females (11.7 vs 9.5 micromol/l, p = 0.07). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with non-diabetics (10.1 vs. 11.2 micromol/l, p = 0.74). We did not see a direct correlation between tHcys concentrations and heart condition as measured by coronary angiography (normal = 11.1 micromol/l, light = 10.5 micromol/l, moderate = 10.9 micromol/l, severe = 10.5 micromol/l; Kruskal-Wallis = 0.45) either. CONCLUSION: These results suggest that tHcys concentration is not a good predictor of the seriousness of ACD in the Puerto Rican patient population.

Total plasma homocysteine concentrations in Puerto Rican patients with presumptive atherosclerotic coronary disease.

BACKGROUND: In Puerto Rico, it has been established that although coronary heart disease is the leading cause of death, the population has a lower incidence of coronary disease than the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. A factor in the lower incidence of coronary disease in Puerto Rico could be a lower total plasma homocysteine concentration (tHcys) in our population. METHODS: We randomly measured tHcys concentrations in seventy-two Hispanic patients who were hospitalized for coronary angiography at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division). RESULTS: The mean tHCys concentration in our patient population is similar than that reported for the Framingham study when adjusted by age (11.2 mumol/L vs. 11.8 mumol/L). In the Puerto Rican population, males had a higher tHcys concentration than females but this difference was not statistically significant (10.9 mumol/L vs. 9.4 mumol/L, p = 0.09). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with nondiabetics (10.1 mumol/L vs. 10.3 mumol/L, p = 0.73). Neither we saw a direct correlation between tHcys concentrations and atherosclerosis as measured by coronary angiography (normal = 10.9 mumol/L, mild = 8.6 mumol/L, moderate = 10.9 mumol/L, severe = 10.5 mumol/L; ANOVA = 0.29). CONCLUSIONS: These results suggest that tHcys concentration is not a good predictor of atherosclerotic coronary disease in our patient population.

Eleven years experience with the Medtronic Hall Valve

We are reporting our experience of eleven years with the Medtronic Hall Valve. Four hundred twenty two patients received the valve with a mortality of 7.9 por cento

Eleven years experience with the Medtronic Hall Valve.

We are reporting our experience of eleven years with the Medtronic Hall Valve. Four hundred twenty two patients received the valve with a mortality of 7.9%.

Readmission in unstable angina.

To determine the characteristics of patients re-admitted after unstable angina (UA) pectoris, 120 consecutive patients hospitalized due to primary UA pectoris were prospectively studied 22 +/- 3 months after discharge. The patients were grouped based on the readmission rate. Those in group A (50) had recurrent admissions (mean 2.6, range 2 to 5). Seventy patients (group B) did not have readmissions during the follow-up period. All patients underwent coronary angiogram and symptoms-limited exercise stress test before discharge. The univariate characteristics for readmission were: age over 70 years (p = 0.02), nondiagnostic exercise stress testing (p = 0.03), angiographically diffuse coronary artery disease (p = 0.004), and non-interventional management (P < 0.001). Patients readmitted had increased incidence of myocardial infarction (p = 0.004) but similar survival at 2 years. By regression analysis, important variables for readmission were non-interventional management (Chi-Square = 7.6, p = 0.01), non diagnostic treadmill test (Chi-Square = 6.9, p = 0.03) and diffuse coronary artery disease (Chi-Square = 6.2, p = 0.04). It is concluded that in the interventional era the most important factor for readmission after primary UA pectoris is non-interventional management. Coronary revascularization should not be denied solely on the basis of age.

Opportunistic invasion of the heart in Hispanic patients with acquired immunodeficiency syndrome.

One hundred consecutive patients who died of the acquired immunodeficiency syndrome (AIDS) were studied with an emphasis on the heart. Thirty-two patients showed pathologic changes. The pathologic findings included infection by Histoplasma capsulatum, Toxoplasma gondii, Mycobacterium tuberculosis, cytomegalovirus. Cryptococcus neoformans, and atypical mycobacteria. Noninfectious pathologic findings included nonspecific myocarditis, focal necrosis, focal fibrosis, and acute subendocardial infarction.

Transient elevation of pulmonary arterial pressure induced by sublingual angiotensin converting enzyme inhibitors.

Twelve patients with ischemic heart disease had complete left and right catheterization before and after sublingual captopril. Hemodynamic measurements were ten (10) minutes apart and were monitored for thirty (30) minutes. The heart rate increased from 70 +/- 13 to 76 +/- 11 beats/minute (P = .04). There was no change in the arterial blood pressure, although the systemic vascular resistance decreased from 1500 +/- 400 to 1026 +/- 480 dynes-sec-cm-5 (P < .0001). The pulmonary artery pressure was increased 15 +/- 6 to 25 +/- 5mmHg (P = .005) and the pulmonary vascular resistance increased from 288 + 160 to 376 + 160 dynes-sec-cm-5 (P < .0001). The wedge pressure increased from 7 +/- 2 to 14 +/- 3 mmHg (P = .05). The cardiac output (CO) increased from 5.06 +/- 1.06 to 578 +/- 1.58 Lt/min. (P.05 =. The left ventricular end diastolic volume (LVEDV) increased from 128 +/- 40 to 145 +/- 37cc)P = .002), without change in the end systolic volume (ESV). The ejection fraction (EF) increased from 56 +/- 3 to 61 +/- 4% (P = .02). These pressure changes appeared at two (2) minutes and disappeared after thirty (30) minutes. The study shows that, sublingual captopril produces a transient elevation of the pulmonary artery pressure and resistance.

Lack of interaction of angiotensin converting enzyme inhibitors with muscarinic and neuropeptide Y receptors.

In studies conducted in patients undergoing cardiac catheterizations, some hemodynamic changes were observed after the acute sublingual administration of the angiotensin converting enzyme inhibitors (ACEI) captopril, enalapril, and lisinopril. These changes consisted of an increase in pulmonary artery pressure, pulmonary vascular resistance (PVR) and induction of hypoxia. The pressure changes were transitory and disappeared after 25 min. The possible mechanisms involved in these changes may relate to interactions of the ACEI with peripheral receptor systems for hormones and neurotransmitters. We have thus undertaken the task of evaluating the potential effect of ACEI on biological receptor molecules. We have begun with studies on muscarinic receptors, and the recently characterized neuropeptide Y (NPY) receptors of endothelial cells. Equilibrium binding assays with 3H-QNB have been conducted for muscarinic receptors using rat brain synaptosomes, due to its expression of multiple muscarinic receptors subtypes. In addition 125BH-NPY binding assays were conducted on intact adrenal medullary endothelial cells. Enalapril and captopril, 10(-7) to 10(-3) M, were not able to produce significant inhibition of either muscarinic or NPY receptor probes. The paradoxical changes elicited by sublingual ACEI seems not to involve interaction with muscarinic or NPY receptors.

Cocaine induced myocardial ischemia.

We report a case of myocardial ischemia induced by cocaine. The ischemia probably induced by coronary artery spasm was reversed by nitroglycerin and calcium blocking agents.

Effects of enalapril on ventricular volumes and neurohumoral status after inferior wall myocardial infarction.

The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system and its beneficial modification with the use of angiotensin-converting enzyme inhibin after inferior wall myocardial infarction (MI) was evaluated. Fifty patients with acute inferior MI were randomly assigned to receive 5 mg per day of either enalapril or placebo after admission. Blood tests for neurohormone levels and echocardiograms were performed at initial examination and 4 weeks later. Baseline characteristics were similar in the two groups. Four weeks after randomization, patients treated with enalapril had lower end-diastolic volume (146 +/- 29 vs 167 +/- 15 ml; p = 0.04), end-systolic volume (56 +/- 18 vs 107 +/- 17 ml; p = 0.03), serum norepinephrine levels (320 +/- 93 vs 465 +/- 77 pg/ml; p < 0.01), angiotensin II levels (18 +/- 6 vs 54 +/- 11 pg/ml; p < 0.01), and atrial natriuretic polypeptide levels (106 +/- 9 vs 122 +/- 17 pg/ml; p = 0.05) than patients given placebo. The incidence of heart failure after MI was also lower in this group (4% vs 16%; p = 0.009). Results show that there is early neurohumoral activation in the course of acute inferior wall MI. Enalapril reduces neurohumoral levels and preserves ventricular volumes. These effects were associated with a reduction in the incidence of heart failure 4 weeks after MI in these patients.

Reduction in cardiac conduction velocity delay by angiotensin converting enzyme inhibition in hypertensive patients with left ventricular hypertrophy. Detection by signal averaged electrocardiography.

Hypertensive patients with left ventricular hypertrophy (LVH) have increased prevalence of ventricular arrhythmias. Slow conduction velocity at the level of hypertrophic myocardial cells has been one of the postulated mechanisms for these arrhythmias. To assess the effects of angiotensin converting enzyme inhibition on modification in ventricular conduction velocities, we studied 25 hypertensive patients with LVH using signal averaged electrocardiography (SAECG) in a randomized double-blind placebo controlled and cross-over trial. Data were acquired at baseline and 10 min after a double-blind intravenous infusion of saline placebo or 2.5 mg enalaprilat. Sequential cross-over was done the next day. Root mean square vector was 55 +/- 5 microV at baseline, 55 +/- 5 microV after placebo and 54 +/- 4 microV after enalaprilat (P = NS). Low amplitude signal < 40 msec was 45 +/- 4 msec at baseline, 45 +/- 4 msec after placebo, and 43 +/- 4 msec after enalaprilat (P = NS). There was no change in filtered QRS (fQRS) duration between baseline (113 +/- 10 msec) and placebo (113 +/- 11 msec) measurements. However, after enalaprilat infusion, there was a significant reduction in fQRS to 106 +/- 7 msec (P = .04), and five patients (20%) with late potentials had normalization of this feature (P = .001). The data suggest that angiotensin converting enzyme inhibition with enalaprilat reduces conduction velocity delay in hypertensive patients with LVH.

AIDS and the heart in the Caribbean: a silent entity.

PIP: Autopsies were performed by the cardiac pathology laboratory of 74 of 100 consecutive AIDS patients who died in Puerto Rico. The 32 with cardiac pathology are reviewed here. There were 27 males and 5 females, averaging 33 years old. 84% were heroin users and/or homosexual, and of the remaining 16%, 2 had heroin users and/or homosexual, and of the remaining 16%, 2 had received blood transfusions. The immediate cause of death was either respiratory or nervous system failure. One case of pericardial effusion (300 ml) associated with pleural effusion and ascites was found, but it was not clinically evident. 6 had cardiomegaly defined by cardiac mass 350 gm in males or 300 gm in females. There were no EKG findings other than sinus tachycardia with occasional ventricular premature beats. The most common pathological finding was nonspecific myocarditis. There were 5 cases with histoplasma showing cardiac foci of histiocytes, 3 with cardiac toxoplasma foci, 3 with mycobacterium granulomas in the myocardium or pericardium, 2 with cytomegalovirus myocarditis with intranuclear inclusions, 2 with cryptococcus neoformans, and 1 with atypical mycobacteria in the myocardium. 2 additional patients had coagulation necrosis of myocardial fibers. These results indicate that myocarditis is common in AIDS patients in Puerto Rico, especially in intravenous heroin users, and its causes are multiple. The clinical picture in terms of congestive heart failure or arrhythmias, however, is silent.^ieng

The use of biosensors in pacemaker technology: experience with a ventricular rate responsive pacemaker.

Ten elderly patients each had a ventricular rate responsive pulse generator (Activitrax) placed in them to help correct severe conduction abnormalities; none had suspected ischemic heart disease. The pulse generator was programmed to a maximal pacing rate of 125 ppm, a medium activity threshold, and a rate response of 6. Six weeks after implantation of the pulse generator, the patients were evaluated before exercising and again when the pacing rate reached 125 ppm. The evaluation protocol included an M-mode echocardiogram from which the following measurements were taken: the left ventricular end-diastolic volume (EDV), the end-systolic volume (ESV), the ejection fraction (EF), and the peak systolic pressure/end-systolic volume (PSP/ESV). The numerical values were recorded, calculated, and compared statically with the following results: the EDV increased from 91 +/- 10 to 125 +/- 20 cc (p less than .05); the ESV decreased from 64 +/- 10 to 24 +/- 6 cc (p less than .005); the EF increased from 41 +/- 5 to 61 +/- 10% (p less than .05); and the PSP/ESV ratio increased from 1.70 +/- 1 to 4.10 +/- 2 mm Hg/cc (p = 10). Also, during the maximal pacing rate, the septum of all patients showed paradoxical septal motion. All patients in our study have been asymptomatic and have shown an increase in their exercise capacity. We conclude that during exercise the left ventricular function ins influenced more by heart rate than by AV synchrony, as indicated by an elevated EDV in most patients.