Prevalence of coronary calcification in relation to age, gender and risk factor profile in the insight population

Calcium controls numerous events within the vessel wall. Permeability of the endothelium is calcium dependent. Calcium is also essential for penetration of low-density lipoprotein particles through the endothelium as well as the monocytes that travel through the subendothelial space. Other calcium-dependent processes include platelet activation and adhesion, vascular smooth muscle proliferation and migration, and synthesis of fibrous connective tissue in the subendothelial space. Current evidence indicates that calcium channel blockers retard the development of atherosclerosis in monkeys and rabbits. Human trials have evaluated sequential coronary angiograms in patients undergoing coronary angiography for symptomatic coronary artery disease. Double helix computerised tomography is a non-invasive technique that can detect, measure and compare calcification in the coronary arteries. Our objectives are to determine whether the use of nifedipine vs diuretics in hypertensive patients at high risk of coronary calcification will arrest or slow the progression of calcification in the coronary arteries, and to assess the effect of the two drugs on left ventricular hypertrophy, and left ventricular mass as well as on changes in left ventricular function.

Comparison of left ventricular function using isometric exercise Doppler echocardiography in competitive runners and weightlifters versus sedentary individuals

It is unclear whether cardiovascular responses to heavy isometric exercise are changed by intensive training. We evaluated the effects of this type of exercise on left ventricular (LV) function in athletes engaged in static and dynamic sport, compared with sedentary persons, and looked for peculiarities in static athletes' responses that might reflect adaptive mechanisms to their specific activity. The study population comprised 45 men (age 24 +/- 5 years): 29 dynamic and 16 static athletes (runners and weightlifters, respectively). The control group consisted of 20 age and gender-matched healthy sedentary persons. All performed 50% of maximal voluntary contraction on a whole-body isometric exercise device for 2 minutes. Echocardiographic calculations were determined at rest and exercise. Upon exercise, stroke volume, cardiac output, end-diastolic volume, and ejection fraction increased significantly in athletes, while end-systolic volume and systemic vascular resistance decreased. In sedentary persons, stroke volume and resistance remained unchanged, cardiac output and LV volumes increased, and ejection fraction decreased from 67 +/- 5% to 60 +/- 5% (p <0.01 compared with rest; p <0.0001 compared with athletes). Whereas peak flow velocity decreased from 103 +/- 10 to 81 +/- 6 cm/s in sedentary persons, it increased from 112 +/- 9 to 126 +/- 8 cm/s in the static group and from 120 +/-3 to 126 +/- 9 cm/s in the dynamic athletes (p <0.0001 compared with the sedentary group). Mean acceleration decreased in the sedentary group, remained unchanged among the dynamic athletes, and increased among the static athletes. We conclude that cardiovascular responses to heavy isometric exercise are modified by intensive training. Athletes, taken as a group, react differently and adapt better than sedentary individuals. Moreover, among them, those involved in static sport show an improved cardiovascular adaptation to this type of exercise.

Exercise echocardiography in postmenopausal hormone users with mild systemic hypertension

Rest and exercise echocardiography (at dynamic and isometric exercise) were performed in 30 postmenopausal women (aged 54 +/- 4 years) with borderline to mild hypertension. They were then divided into 2 groups: 17 women who started oral hormone replacement therapy (0.625 mg/day conjugated estrogens or 2 mg/day estradiol) and a control group of 13 nonusers. After 6 to 9 months, a second echocardiography was performed in 26 women (4 withdrew). There were only a few changes in values obtained in the 12 controls at the end of follow-up compared with baseline. Primarily, these changes included a slight decrease in systolic blood pressure at rest and on exercise. Several significant morphologic and hemodynamic alterations appeared in 14 hormone users. Left ventricular cavity dimensions and mass became smaller: mean end-diastolic diameter decreased from 45.9 +/- 3 mm at baseline to 44.4 +/- 3 mm at study termination (p = 0.007). The corresponding values for end-systolic diameter were 25.8 +/- 4 mm and 23.9 +/- 4 mm (p = 0.006); for left atrium diameter, it was 34.5 +/- 4 mm and 32.5 +/- 4 mm (p = 0.001); for left ventricular wall width, it was 19.9 +/- 2 mm and 19.3 +/- 2 mm (p = 0.02); for left ventricular mass, it was 197 +/- 28 g and 179 +/- 32 g (p = 0.006). The resting aortic blood flow velocity and acceleration increased: 119 +/- 18 cm/s before therapy versus 129 +/- 23 cm/s while on hormone substitution (p = 0.04), and 13.6 +/- 3 m/s2 versus 16.5 +/- 4 m/s2 (p = 0.008), respectively. Mean rest to peak exercise systolic blood pressure difference became smaller after hormones: 39 +/- 19 mm Hg versus 28 +/- 13 mm Hg (p = 0.03) during dynamic exercise, and 43 +/- 22 mm Hg versus 25 +/- 13 mm Hg (p = 0.004) during isometric exercise. The above data probably indicate that with hormone replacement therapy, there is an improvement in cardiac function both at rest and during exercise.

Absence of coronary calcification on double-helical CT scans: predictor of angiographically normal coronary arteries in elderly women?

PURPOSE

To test the hypothesis that angiographically normal coronary arteries in elderly women are identifiable by the absence of coronary calcification on double-helical computed tomographic (CT) scans.

MATERIALS AND METHODS

Forty-eight consecutive women (age range, 60-76 years) underwent coronary angiography for chest pain evaluation, as well as double-helical CT. Thirty women (mean age, 65 years +/- 5) had coronary artery disease (CAD), defined as any angiographic disease, and 18 women (mean age, 66 years +/- 4) had angiographically normal coronary arteries.

RESULTS

Women with angiographically normal coronary arteries had lower coronary calcification scores than those of patients with CAD: 5.7 +/- 11 versus 580 +/- 634, respectively (P = .0004). Seven women with angiographically normal coronary arteries demonstrated mild coronary calcification (score < 50). Of the 11 women without coronary calcification, none had CAD. Thus, the absence of coronary calcification on double-helical CT scans in elderly women was predictive of angiographically normal coronary arteries with 61% sensitivity, 100% specificity, and 85% accuracy.

CONCLUSION

Double-helical CT is an accurate, noninvasive modality for diagnosing angiographically normal coronary arteries in elderly symptomatic women.

Shortened Doppler-derived mitral A wave deceleration time: an important predictor of elevated left ventricular filling pressure

OBJECTIVES

The aim of this study was to investigate whether a new variable of mitral inflow, A wave deceleration time, identifies patients with elevated left ventricular filling pressures.

BACKGROUND

In patients with an elevated left ventricular end-diastolic pressure, the increase in left ventricular pressure after atrial contraction rapidly exceeds left atrial pressure, resulting in abrupt cessation of the A wave. Therefore, we postulated that a shortening of A wave deceleration time might be a marker for elevated end-diastolic pressure.

METHODS

Adequate pulsed Doppler mitral inflow velocities could be recorded in 40 of 44 consecutive patients undergoing cardiac catheterization with capillary wedge pressure in 20 patients, and within 1 h after left ventricular end-diastolic pressure recording in 20. Fifteen healthy volunteers were also studied.

RESULTS

Left ventricular end-diastolic pressure was 8 to 35 mm Hg, and mean pulmonary wedge pressure was 6 to 37 mm Hg. Close correlations were found between A wave deceleration time and mean pulmonary wedge pressure (r = -0.87) and left ventricular end-diastolic pressure (r = -0.74). There were modest correlations between both pressures and peak E/A, E wave deceleration time and A wave duration, respectively; r = 0.59, -0.30 and -0.58 for capillary wedge and r = 0.25, -0.38 and -0.49 for end-diastolic pressures. A wave deceleration time </= 60 ms predicted left ventricular end-diastolic and mean pulmonary wedge pressures > 18 mm Hg, respectively, with a sensitivity of 67% and 89% and specificity of 100% for both.

CONCLUSIONS

A shortened Doppler mitral inflow A wave deceleration time is a useful index of elevated left ventricular filling pressure.

Coronary calcium as a reliable tool for differentiating ischemic from nonischemic cardiomyopathy

In conclusion, the presence or absence of coronary calcium as detected by this rapid technique represents a simple and reliable noninvasive sign for the differential diagnosis between ischemic and nonischemic DC.

Calcification of coronary arteries: detection and quantification with double-helix CT

PURPOSE

To evaluate the accuracy of double-helix computed tomography (CT) in coronary artery calcification detection and quantification.

MATERIALS AND METHODS

One hundred sixty patients with coronary disease (135 men, 25 women; age range, 45-62 years), of whom 138 had obstructive (stenosis of > 50% of diameter; n = 129) or mild (< 50% stenosis; n = 9) coronary artery disease (CAD) and 22 had normal coronary arteries (per angiographic findings), and 56 age-matched healthy control subjects underwent double-helix CT.

RESULTS

Double-helix CT findings indicated that calcification was significantly more prevalent in patients with CAD (> 83%) than in patients with normal coronary arteries (27%) or in healthy control subjects (34%; P < .01). Sensitivity in detecting obstructive CAD was high (91%); however, specificity was low (52%) because of calcification in nonobstructive lesions. Comparison of double-helix CT and angiographic findings indicated that double-helix CT was 84% accurate with positive and negative predictive values of 89% and 59%, respectively.

CONCLUSION

Double-helix CT is a useful noninvasive method for detection and quantification of coronary artery calcification.

Failure of transesophageal echocardiography to visualize a large mitral prosthesis vegetation detected solely by transthoracic echocardiography

Transesophageal echocardiography yields a highly accurate diagnosis in the detection of valvular vegetations. We describe a case in which omniplane transesophageal echocardiography failed to demonstrate a large vegetation protruding from a Starr-Edwards mitral prosthesis, toward the left ventricular outflow tract. The vegetation could be detected solely by transthoracic echocardiography.

Improved posterobasal segment function after thrombolysis is associated with decreased incidence of significant mitral regurgitation in a first inferior myocardial infarction

OBJECTIVES

This study was designed to investigate the association between wall motion abnormalities and the occurrence of ischemic mitral regurgitation in patients with a first inferior or posterior myocardial infarction and to reassess the role of thrombolytic treatment in these patients.

BACKGROUND

We previously demonstrated that thrombolytic therapy reduces the incidence of significant mitral regurgitation in patients with a first inferior myocardial infarction, but the mechanisms responsible for this decrease were not clear.

METHODS

Wall motion score on two-dimensional echocardiography (16 segments) and mitral regurgitation grade (0 to 3) on Doppler color flow imaging were assessed in 95 patients (in 47 after thrombolysis) at 24 h, 7 to 10 days and 1 month after myocardial infarction. Significant mitral regurgitation was defined as moderate or severe (grade 2 or 3).

RESULTS

Multivariate analysis revealed that the presence of an advanced wall motion abnormality of the posterobasal segment of the left ventricle was the most significant independent variable associated with significant mitral regurgitation: odds ratio (OR) 15.0, 90% confidence interval (CI) 1.4 to 165.6 at 24 h; OR 2.8, CI 0.9 to 9.3 at 7 to 10 days; OR 4.2, CI 1.2 to 11.4 at 1 month. Thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment at 24 h (55% vs. 75%, OR 0.5, CI 0.2 to 0.99), 7 to 10 days (44% vs. 73%, OR 0.3, CI 0.1 to 0.7) and 1 month (36% vs. 56%, OR 0.4, CI 0.2 to 0.9).

CONCLUSIONS

There is a strong association between advanced wall motion abnormalities in the posterobasal segment and significant mitral regurgitation. In this study group, thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment and thereby reduced the incidence of significant mitral regurgitation.

Improved left ventricular function after thiamine supplementation in patients with congestive heart failure receiving long-term furosemide therapy

PURPOSE

We have previously found thiamine (vitamin B1) deficiency in patients with congestive heart failure (CHF) who had received long-term furosemide therapy. In the present study, we assessed the effect of thiamine repletion on thiamine status, functional capacity, and left ventricular ejection fraction (LVEF) in patients with moderate to severe CHF who had received furosemide in doses of 80 mg/d or more for at least 3 months.

PATIENTS AND METHODS

Thirty patients were randomized to 1 week of double-blind inpatient therapy with either i.v. thiamine 200 mg/d or placebo (n = 15 each). All previous drugs were continued. Following discharge, all 30 patients received oral thiamine 200 mg/d as outpatients for 6 weeks. Thiamine status was determined by the erythrocyte thiamine-pyrophosphate effect (TPPE). LVEF was determined by echocardiography.

RESULTS

TPPE, diuresis, and LVEF were unchanged with i.v. placebo. After i.v. thiamine, TPPE decreased (11.7% +/- 6.5% to 5.4% +/- 3.2%; P < 0.01). LVEF increased (0.28 +/- 0.11 to 0.32 +/- 0.09; P < 0.05), as did diuresis (1,731 +/- 800 mL/d to 2,389 +/- 752 mL/d; P < 0.02), and sodium excretion (84 +/- 52 mEq/d to 116 +/- 83 mEq/d, P < 0.05). In the 27 patients completing the full 7-week intervention, LVEF rose by 22% (0.27 +/- 0.10 to 0.33 +/- 0.11, P < 0.01).

CONCLUSIONS

Thiamine repletion can improve left ventricular function and biochemical evidence of thiamine deficiency in some patients with moderate-to-severe CHF who are receiving longterm furosemide therapy.

Echocardiographic assessment of prosthetic valve endocarditis

Prosthetic valve endocarditis is still a very serious complication, carrying an incidence of death between 30 and 70% in some series. Therefore early and accurate diagnosis is crucial. Early (less than 60 days post surgery) endocarditis is usually a fulminant disease, where staphylococcal infection is most common. Late prosthetic endocarditis resembles more closely other forms of the disease. Conventional echocardiography is useful in the evaluation of prosthetic valve function, but it is very limited in the demonstration of infective lesions, primarily because of acoustic shadowing. Transoesophageal echocardiography (TE) enables high resolution imaging of the heart without chest wall interference, and viewing of the heart from the posterior (atrial, low pressure) side, where most of the vegetations are expected to be found in both mitral and tricuspid positions. It also enables better visualization of the left ventricular outflow tract, where aortic prosthetic vegetations tend to be present. Furthermore, transoesophageal echocardiography allows accurate diagnosis of some of the common complications of endocarditis: abscess/cavity formation; mycotic aneurysm; prosthetic valve dehiscence and regurgitation. In spite of these advantages, limitations should be recognized. Struts are commonly seen on transoesophageal echocardiography following surgery and should not be confused with vegetations. Similarly, normal prosthetic regurgitation should not be confused with paravalvar leakage. Nevertheless, transoesophageal echocardiography, when expertly used, changes the possibility for early and more accurate diagnosis of prosthetic valve endocarditis dramatically. Transoesophageal echocardiography should be included among the major criteria in the diagnosis and follow-up of prosthetic valve endocarditis.

Disappearance of a syndrome: Dressler's syndrome in the era of thrombolysis

The incidence of the post-myocardial infarction syndrome (Dressler's syndrome) among thrombolized patients has not been established yet. To clarify this issue we prospectively studied 201 consecutive patients with acute myocardial infarction who had undergone recombinant tissue-type plasminogen activator therapy followed by 5 days of heparin administration. All patients were followed for at least 3 months for clinical signs of Dressler's syndrome. None of the 148 patients (76%) who showed clinical signs of early reperfusion had Dressler's syndrome. The sole patient in the group who manifested the syndrome developed it 3 weeks following extensive anterior myocardial infarction with no evidence of reperfusion. Although 4 patients manifested signs of early pericarditis, none developed the syndrome. We conclude that Dressler's syndrome has in fact been rendered a rare phenomenon among patients who benefit from thrombolytic therapy.

Persistence of normal right ventricular Doppler filling pattern early after tricuspid valve excision

Two patients with acute tricuspid bacterial endocarditis in which a normal right ventricular Doppler filling pattern was demonstrated early following valvectomy are reported. After surgery, on pulsed Doppler examination, the sample volume positioned at the right atrioventricular level revealed a normal M-shaped filling pattern. A pathologic monophasic pattern was documented a few months later. Our findings suggest that early after surgery the preserved gradient throughout ventricular diastole leads to a passive and active filling similar to normal. Only at a later stage is the grossly dilated right atrium unable to maintain active filling, and the 'A' wave disappears despite the fact that sinus rhythm is maintained. Tricuspid valve diastolic motion represents a product of the several factors that determine atrioventricular gradient, but the valve itself appears not to be involved in the generation of a normal filling pattern.

Quantitative myocardial ultrasonic integrated backscatter measurements during contrast injections

We and others have shown that normal myocardium exhibits 4 to 5 dB diastolic-to-systolic cyclic variation (CV) of integrated backscatter. To investigate the effect of intramyocardial contrast on integrated backscatter, we injected 5% sonicated albumin, containing microbubbles in the range of 5 microns in diameter, into the left atrium in nine open-chest dogs. The dogs were anesthetized and placed in the right lateral decubitus position on a specially designed table with a cutout allowing ultrasound imaging from below. Ultrasonic data was obtained from the right precordium by use of a prototype M-mode integrated backscatter system implemented in a commercially available two-dimensional system. Usable data were obtained in eight of nine dogs. Integrated backscatter increased up to 13 dB after contrast injections. There was a significantly decreased CV of integrated backscatter during myocardial contrast in all eight dogs. The mean level of CV of integrated backscatter for the eight dogs decreased from 4.7 dB (530 beats analyzed) without contrast to 2.8 dB during contrast (436 beats analyzed). There was a trend to greater CV at higher levels of contrast. Septal excursion, as measured by M-mode echocardiography simultaneously with integrated backscatter by the same ultrasound beam, was similar with and without contrast (mean 8.2 vs 8.3 mm). Thus left atrium contrast injection produces quantitatively measurable integrated backscatter effects. Cyclic variation of integrated backscatter decreases with contrast. However, at higher contrast levels the decrease tends to be smaller. These effects should be considered during quantitative tissue characterization and myocardial contrast studies.

Tricuspid valve surgery: recent experience at the Chaim Sheba Medical Center

From 1 January 1989 to 30 June 1992, 35 patients underwent cardiac surgery that included a tricuspid valve (TV) procedure. All had severe TV dysfunction documented by echocardiography, and were in NYHA functional class III-IV. The etiology of TV dysfunction was rheumatic-functional in 19 patients, rheumatic-organic in 13, and infective in 3. Nineteen (54%) had had at least one previous cardiac operation, and in 29 an associated procedure (MVR, AVR, DVR, DVR + CABG) had been performed. The TV was repaired in 27 patients, was replaced by a bioprosthesis in 7, and was excised in 1. There were three (8.6%) operative and two late deaths. Except for two, all surviving patients are in NYHA functional class I-II. In two patients with organic lesions who underwent repair, residual moderate tricuspid regurgitation was observed. We conclude that in these critically ill patients TV surgery can be performed with acceptable results. Long-term fate of a bioprosthesis in the tricuspid position is yet to be determined.

Effect of thrombolytic therapy on the evolution of significant mitral regurgitation in patients with a first inferior myocardial infarction

OBJECTIVES

This study was designed to test the hypothesis that reperfusion therapy with thrombolysis will prevent the development of significant mitral regurgitation in patients with inferior myocardial infarction.

BACKGROUND

The value of thrombolytic therapy in patients with inferior or posterior wall myocardial infarction has been controversial. We hypothesized that successful reperfusion therapy with intravenous thrombolysis may reduce the incidence and severity of postinfarction mitral regurgitation in this patient group.

METHODS

We prospectively studied 104 patients with a first inferior myocardial infarction. Thrombolytic therapy was administered to 55 patients (treatment group) 3.2 +/- 2.1 h after the onset of symptoms. The other 49 patients formed the control group. Doppler echocardiographic color flow imaging was performed in all patients within 24 h, at 7 to 10 days and at 28 to 30 days after myocardial infarction. Significant mitral regurgitation was defined as moderate or severe (grade 2 or 3).

RESULTS

No significant differences in baseline clinical characteristics were observed between the treatment and control groups. The overall incidence rates of significant mitral regurgitation at 24 h, 7 to 10 days and at 28 to 30 days were 10 (10%) of 104 patients, 18 (17%) of 104 patients and 11 (11%) of 100 patients, respectively. Multivariate analysis reveals the following independent predictors of the occurrence of significant mitral regurgitation: female gender (at 7 to 10 days, odds ratio 5.3, 90% confidence interval [CI] 1.8 to 15.5; at 28 to 30 days, odds ratio 3.7, 90% CI 1.1 to 12.7), heart failure (at 7 to 10 days, odds ratio 7.7, 90% CI 2.2 to 26.9) and transient complete atrioventricular block (at 24 h of myocardial infarction, odds ratio 5.8, 90% CI 1.2 to 27). Compared with the control group, the treatment group exhibited marked reduction in the incidence of significant mitral regurgitation at 24 h (16% vs. 4%; odds ratio 0.1, 90% CI 0.0 to 0.7); at 7 to 10 days (24% vs. 11%; odds ratio 0.3, 90% CI 0.1 to 0.9) and at 28 to 30 days (15% vs. 7%; odds ratio 0.4, 90% CI 0.1 to 1.6). Severe (grade 3) mitral regurgitation developed in five patients in the control group but in no patient in the treatment group.

CONCLUSIONS

Thrombolytic therapy in the patients with a first inferior myocardial infarction was associated with a reduced incidence of significant mitral regurgitation. These results support the use of such therapy in patients with inferior myocardial infarction.

Left ventricular pseudohypertrophy in cardiac tamponade: an echocardiographic study in a canine model

OBJECTIVES

This study was designed to establish whether left ventricular pseudohypertrophy in cardiac tamponade can be reproducibly induced in an experimental canine model and to investigate the mechanism of its production.

BACKGROUND

Past experimental and clinical studies have shown reduction of ventricular volumes resulting from cardiac tamponade. Left ventricular pseudohypertrophy, a transient thickening of myocardial walls, was recently described as a new echocardiographic sign of cardiac tamponade.

METHODS

Cardiac tamponade was induced in seven anesthetized open chest dogs with serial bolus injections of 50 ml each of 0.9% saline solution into the pericardial sac. Under hemodynamic monitoring, M-mode and two-dimensional echocardiographic measurements were performed from a right parasternal window at each stage of graded cardiac tamponade.

RESULTS

There was a progressive increase of interventricular septal and posterior wall diastolic thickness. Mean wall thickness (interventricular septal thickness + posterior wall thickness divided by 2) was 9.8 +/- 1.3 mm at baseline, 14.3 +/- 0.9 mm at peak tamponade and 9.0 +/- 1.5 mm after fluid withdrawal (p < 0.0001). Mean wall thickness correlated directly with the severity of cardiac tamponade, as estimated from the level of right arterial pressures (r = 0.75 and p < 0.0001), and with the decrease of left ventricular cavity volume (r = -0.67 and p < 0.0001). Left ventricular mass did not change significantly.

CONCLUSIONS

Left ventricular pseudohypertrophy is a constant manifestation of cardiac tamponade in a canine model. The degree of myocardial thickening correlates with the reduction of ventricular dimensions and with the severity of hemodynamic compromise, representing a constant facet of heart remodeling in cardiac tamponade.