Abnormalities of dynamic ventricular shape change in patients with aortic and mitral valvular regurgitation: assessment by Fourier shape analysis and global geometric indexes

The normal cardiac cycle is associated with dynamic changes in left ventricular shape, which can be disturbed in disease states. To assess the influences of diastolic volume, percent ejected volume, and abnormalities of acute or chronic systolic loading on general and detailed chamber geometry, we studied dynamic shape change recorded by x-ray contrast ventriculography in both normal patients and those with aortic (AR) or mitral (MR) valve regurgitation. While both lesions increased diastolic volume, the character of load throughout ejection differed markedly. Detailed cavity geometry was assessed by a Fourier analysis technique and general shape by eccentricity and circularity indexes. Normal hearts, showed increased systolic elongation by all indexes. AR patients displayed a similar rise in eccentricity during ejection; however, the extent of shape change when measured by Fourier and circular indexes was reduced. In contrast, MR patients displayed enhanced systolic shape change, particularly in chamber elongation. Neither simple eccentricity of circular indexes adequately differentiated these shape abnormalities, whereas detailed Fourier geometric analysis precisely characterized the abnormalities of shape change in these two diseases. Relations between the extent of shape change and ejected volume for each patient group revealed significantly more systolic deformation with a different shape versus volume relation for the MR hearts as compared with AR and controls. Thus, while dynamic left ventricular shape is certainly influenced by the extent of volume change, it also varies independently from volume related to the specific nature of loading during ejection.

Left ventricular wall motion during the isovolumic relaxation period

Technically adequate left ventricular cineangiograms obtained in the 30 degree right anterior oblique (RAO) projection from 100 consecutive patients with chest pain were studied for the presence of left ventricular wall motion during the isovolumic relaxation period. Obstructive coronary artery disease was found in 59 and normal coronary arteries in 41 patients. Systolic contraction abnormalities were present in 52 of the 100 patients. Outward left ventricular wall motion during the isovolumic relaxation period was observed in 83 patients. This outward motion, termed segmental early relaxation phenomenon (SERP), was localized in 81. In 29 patients SERP was accompanied by a simultaneous inward motion that was apparent in the 30 degree RAO position in another part of the left ventricle. In ventricles with systolic contraction abnormalities SERP tended to occur in the normally contracting areas (25 of 39 patients). When the abnormal systolic contraction was extensive, SERP occurred infrequently (4 of 16 patients). In this group of patients with chest pain, whether or not they had coronary artery disease, outward left ventricular wall motion occurred commonly during isovolumic relaxation. It appears to be a normal variation of left ventricular relaxation.

Massive pulmonary embolism associated with a right ventricular myxoma

A 12 year old boy had a massive pulmonary embolism associated with a right ventricular myxoma. This caused complete occlusion of the main trunk of the left pulmonary artery and of a branch of the right pulmonary artery supplying the basal area of the lower lobe of the right lung. The patient died despite two surgical attempts to remove the tumor clots. To our knowledge this constitutes the first report of a massive pulmonary artery embolism associated with a right ventricular myxoma.

Simvastatin releases Ca2+ from a thapsigargin-sensitive pool and inhibits InsP3-dependent Ca2+ mobilization in vascular smooth muscle cells

Simvastatin (SV), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity inhibits migration and proliferation of vascular smooth muscle cells (SMC). To investigate whether these effects of SV are related to inhibition of cell calcium mobilization, cultured SMC obtained from rat aorta were loaded with Fura-2 to determine the basal cytosolic free calcium levels ([Ca2+]i) and the agonist-stimulated Ca2+ mobilization. SV (20 mu M) transiently increased cytosolic free calcium, an effect that depends mainly on intracellular calcium release (68%). This effect of SV was markedly reduced (75%) by thapsigargin, an inhibitor of the Ca2+ ATPase of inositol 1,4,5-triphosphate (InsP3)-sensitive calcium pools. Incubation of cells with SV (15 min) inhibited the mobilization of Ca2+ by angiotensin II, platelet-derived growth factor, and vasopressin (IC50 = 5 mu M). SV did not affect inositol trisphosphate (InsP3) levels or modify its generation by angiotensin II (Ang II) and vasopressin. Furthermore, in saponin-permeabilized cells, SV abolished the release of calcium by 2,3-dideoxy-InsP3. SV reduced the effect of thapsigargin on InsP3-sensitive stores by 67%, suggesting that SV depletes these calcium pools. The inhibitory effect of SV on calcium mobilization was prevented by coincubation of cultured cells (24 h) with 1 mM mevalonic acid, the product of HMG-CoA reductase activity. These results support the notion that SV inhibits [corrected] the migration and proliferation of SMC by directly affecting cell Ca2+.

Altered vascular function in early stages of heart failure in hamsters

BACKGROUND

Congestive heart failure is a clinical condition associated with alterations in the normal balance of neurohumoral agents and factors acting on the vascular wall. The etiology of this condition, however, remains largely undefined. To help elucidate the pathophysiology of this disease, vascular function and angiotensin-converting enzyme activity were evaluated in 2-month-old Syrian cardiomyopathic hamsters (SCHs) that had not yet developed heart failure. Age-matched normal hamsters were used as control hamsters.

METHODS AND RESULTS

Vascular function studies included determinations of contractile responses of aortic rings to 0.1 microM angiotensin II and 0.1 microM norepinephrine. In addition, endothelial function was evaluated by the vasorelaxant action of acetylcholine on norepinephrine-precontracted aortic rings. The results indicate that the pressor effect of angiotensin II (0.1 microM) was 35% greater in aortic rings from SCRs than that observed in control animals. This effect is specific for angiotensin II because the contraction induced by NE (0.1 microM) was similar in both of these strains. Angiotensin-converting enzyme activity was three-fold higher in aorta homogenates from SCHs but normal in plasma and heart tissue when compared with control hamsters. Aortic ring preparations from SCHs also exhibited endothelial dysfunction because the maximal relaxation elicited by 10 microM acetylcholine was reduced 53%. Concentration-response curves with acetylcholine yielded EC50 values that were threefold lower in SCHs (97.2 +/- 0.1 nM) than in control animals (286 +/- 7 nM). Indomethacin (1 microM) increased the vasorelaxant effect of acetylcholine 28% in SCHs and shifted to the left the concentration-response curve of this agonist, suggesting an increased relaxation with the cyclooxygenase inhibitor. No effect of indomethacin on acetylcholine-induced relaxation was observed in control animals. Sodium nitroprusside induced similar relaxations in both control animals and SCHs, suggesting that the vascular smooth muscle response is normal in SCR.

CONCLUSIONS

Altogether these results point to a state of enhanced vascular contractility in young SCHs that could predispose these animals to develop heart failure, the enhanced vascular contractility could result from increased activity of the local renin-angiotensin system, augmented vascular response to angiotensin II, reduced nitric oxide synthesis, and enhanced production of prostaglandins.

Relationship between NO synthesis, arginine transport, and intracellular arginine levels in vascular smooth muscle cells

The present study was designed to evaluate the relevance of arginine transport in nitric oxide (NO) synthesis in vascular smooth muscle cells. For this purpose, NO synthesis and arginine transport (system B0,+ and y+) were evaluated in cells treated with IL-1beta or angiotensin II (Ang II). In addition, the effects of 5 mM lysine and glutamine, competitive inhibitors of systems y+ and B0,+ respectively, were examined. L-arginine transport was estimated with 3H-labelled arginine and NO was determined with the Griess reagent. These studies were done in control conditions, arginine-starved cells, and in cells incubated in media containing 10 mM arginine. Our data indicate that induction of NO biosynthesis by IL-1beta depends on external arginine when cells are arginine-depleted for 24 hours. The concentration of arginine producing half maximal activation of NO synthesis in arginine-depleted cells ([arginine]i < 10 microM) was 41.1 +/- 18 microM. By contrast, in normal culture conditions, NO synthesis occurred independently of arginine transport. Neither 5 mM lysine or glutamine which abolished arginine transport through systems y+ and B0,+, respectively, reduced nitrite release in cells incubated in normal media. This suggests that the relevance of arginine uptake to NO synthesis depends on the status of intracellular arginine pools. Intracellular arginine concentrations were not affected by the stimulation of NO production using IL-1beta or its inhibition using Ang II, but were markedly reduced by arginine starvation for 48h. Aspartate levels were also reduced by arginine-depletion, but were not affected in cells incubated with 10 mM arginine. By contrast, glutamate levels were reduced in arginine-starved cells and were increased in cells incubated in arginine-supplemented medium. Ornithine levels were markedly increased by arginine supplementation. Altogether, these findings indicate that NO synthesis is normally independent of membrane transport. However in arginine-depleted cells, membrane transport is essential for NO synthesis. It is concluded that arginine transport is required for the long-term maintenance of intracellular arginine pools.

Effects of enalapril on heart failure in hypertensive patients with diastolic dysfunction

Ten hypertensive patients with symptoms of heart failure and normal systolic function but with diastolic dysfunction were treated with 10 mg enalapril twice a day for 9 +/- 3 months to evaluate the effects of this agent alone on heart failure induced by diastolic dysfunction. After therapy, all patients improved and echocardiographic parameters of diastolic dysfunction became normalized. It is concluded that enalapril appears to be useful in the treatment of heart failure in hypertensive patients with normal systolic function and diastolic dysfunction.

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.

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.

Unusual roentgenographic manifestation of Pneumocystis carinii pneumonia

An immunologically deficient patient had two large nodular densities on the chest x-ray film. On autopsy, large solid accumulations and diffuse pneumonitis with Pneumocystis carinii were found. This represents an unusual manifestation of Pneumocystis carinii.

[Total plasma homocysteine concentrations in Puerto Rican patients with ischemic heart disease]

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.

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.

Parallel regulation of arginine transport and nitric oxide synthesis by angiotensin II in vascular smooth muscle cells role of protein kinase C

Experiments were performed to characterize arginine transport in vascular smooth muscle cells (SMCs) and the effect of angiotensin II (Ang II) on this process. In addition, the role of arginine transport in the cytokineinduced nitric oxide (NO) production was assessed. Arginine transport takes place through Na(+)-independent (≈60%) and Na(+)-dependent pathways (≈40%). The Na(+)-independent arginine uptake appears to be mediated by system y(+) because of its sensitivity to cationic amino acids such as lysine, ornithine and homoarginine. The transport system was relatively insensitive to acidification of the extracellular medium. By contrast, the Na(+)-dependent pathway is consistent with system B(0,+) since it was inhibited by both cationic and neutral amino acids (i.e., glutamine, phenylalanine, and asparagine), and did not accept Li(+) as a Na(+) replacement. Treatment of SMCs with 100nM Ang II significantly inhibited the Na(+)-dependent arginine transport without affecting systems y(+), A, and L. This effect occurred in a dose-dependent manner (IC50 of 8.9 ± 0.9nM) and is mediated by the AT-1 receptor subtype because it was blocked by DUP 753, a non-peptide antagonist of this receptor. The inhibition of system B(0,+) by Ang II is mediated by protein kinase C (PKC) because it was mimicked by phorbol esters (phorbol 12-myristate 13-acetate) and was inhibited by staurosporine. Ang II also inhibited the IL-1β induced nitrite accumulation by SMCs. This action was also inhibited by staurosporine and reproduced with phorbol esters, suggesting a coupling between arginine uptake and NO synthesis through a PKC-dependent mechanism. However, arginine supplementation in the medium (10mM) failed to prevent the inhibitory action of Ang II on NO synthesis. These findings suggest that although Ang II inhibits concomitantly arginine transport and NO synthesis in SMCs, the reduction of NO synthesis is not associated with alterations in the cellular transport of arginine.

Effects of enalaprilat on hemodynamics and ventricular activation duration in hypertensive patients with left ventricular hypertrophy: clinical evidence of improved excitation-contraction coupling with angiotensin converting enzyme inhibition in human hypertension

Hypertension is a major risk factor for the development of heart failure. Despite significant progress in our knowledge of the physiopathology of heart failure, the cause for decompensation in patients with left ventricular hypertrophy (LVH) is still obscure. The angiotensin converting enzyme inhibitor enalaprilat has been found to improve electromechanical coupling of heart cells in animal models. To assess the effects of enalaprilat on ventricular electromechanical coupling in humans, we studied the His bundle electrograms and hemodynamics in 22 hypertensive patients with LVH. Patients received either 2.5 mg enalaprilat or saline placebo intravenously in a double-blind protocol. There were no significant changes in heart rate, and atrioventricular and His-Purkinje conduction times. Ventricular activity duration was reduced from 110 +/- 11 msec to 88 +/- 13 msec after enalaprilat administration (P < .01). Enalaprilat decreased peak-systolic and end-diastolic left ventricular pressures, and arterial and pulmonary pressures, as well as pulmonary and systemic vascular resistances. End-systolic wall stress decreased 18% (P < .01), ejection fraction increased 11% (P < .01), and end-diastolic pressure-volume ratio decreased 50% (P < .001) after enalaprilat administration. There were no significant changes in these parameters after saline infusion. It is concluded that enalaprilat reduces ventricular activation duration and improves ventricular performance in hypertensive patients with LVH. Data suggest that enalaprilat significantly improves excitation-contraction coupling in these patients.

Bronchogenic cyst mimicking a pulmonary varix

A 14-year-old boy initially had severe hemoptysis and a coin lesion in the left lower lobe on the chest x-ray film. Pulmonary arteriographic studies suggested the presence of a pulmonary varix. Pathologic examination of the specimen obtained at surgery revealed a bronchogenic cyst. Pulmonary varices are extremely rare. Bronchogenic cysts must be included in the differential diagnosis of these lesions.

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.

Left ventricular function in adults with atrial septal defect

Sixteen patients with secundum atrial defect were catheterized giving emphasis to the analysis of the left ventricle at end systole and mid-ejection. The mean ejection fraction of the group was subnormal 57 + 8% when compared with 30 normal patients (71 + 109) P less than .005. Eight patients showed elevated end-diastolic volumes (156 + 10cc) when compared to our normal group (95% + 10cc) P less than .005. A total of 32 hypokinetic and 35 tardokinetic areas were found. Eight patients were restudied after nitroglycerin (0.4 mg sublingually) with an improvement in the ejection fraction from 54% to 70% (P less than .005) and normalization of most of the hypokinetic areas. No correlation was found between total ejection fraction or total systolic wall motion and the shunt size. Probably these left ventricular wall motion abnormalities are primary and not due to the shunt size.