Coronary arteriographic findings in symptomatic and asymptomatic subjects with coronary artery calcification.

The relation of coronary artery calcification with the presence of symptoms of coronary artery disease and its angiographic severity is not clear. We studied 37 apparently healthy, asymptomatic subjects that were found by digital cinefluoroscopy to have coronary calcium and compared to age- and sex-matched group of patients with coronary calcium and symptomatic coronary artery disease. Normal coronary arteries and non-obstructive lesions only were found in 12/37 (32.4%) and 11/37 (29.7%) asymptomatic subjects vs. 1/37 (2.7%) and 2/37 (5.4%) patients; P<0.001 and P<0.012, respectively. Obstructive lesions were more rare in asymptomatic subjects than in patients, 14/37 (37.8%) vs. 34/37 (91.9%) (P<0.0001), as well as total occlusions, 2/37 (5.4%) vs. 10/37 (27%) (P<0.024). Median worst lesion stenosis was 30% in asymptomatic subjects and 95% in patients (P<0.0001). In asymptomatic usual cardiovascular risk subjects, coronary calcium detection by digital cinefluoroscopy is accompanied by a relatively high probability of obstructive disease, although less severe angiographically than in age- and sex-matched catheterized patients with symptomatic coronary artery disease.

Prevalence of intrapulmonary vascular dilatations in normoxaemic patients with early liver cirrhosis.

BACKGROUND: The aim of this study was to determine the prevalence of intrapulmonary vascular dilatations (IPVD) in normoxaemic patients with early liver cirrhosis and to compare their occurrence in progressive alcoholic versus postviral hepatic insufficiency. METHODS: Pulmonary function tests and arterial blood gas measurements were performed in 75 consecutive patients with cirrhosis of alcoholic and postviral aetiology. Contrast-enhanced echocardiography was used to identify IPVD. RESULTS: All patients were grade A or B in accordance with the Child-Pugh modified classification. Arterial blood gas analyses showed normoxaemia in all patients. Eight of 75 patients (10.7%) had a positive contrast echocardiogram, all with a decreased diffusion capacity (D1CO < 75% of the expected value). The abnormality was more prominent with advancing stage of liver failure (4.5% in grade A versus 19.4% in grade B; P < 0.05) and more common in patients with alcoholic cirrhosis (17.5% in alcoholic versus 2.9% in postviral cirrhosis; P < 0.05). CONCLUSION: In normoxaemic patients with early liver cirrhosis subclinical pulmonary vasodilatation, as assessed with contrast echocardiography, can occur. The finding is more prominent in alcoholic cirrhosis and possibly reflects an advancing degree of liver insufficiency.

Repolarization abnormalities with prolonged hyperventilation in apparently healthy subjects: incidence, mechanisms and affecting factors.

Brief hyperventilation is occasionally accompanied by repolarization abnormalities in subjects without apparent heart disease. However, the effect of prolonged hyperventilation on repolarization abnormalities is not clearly defined. We analysed the repolarization abnormalities induced by prolonged hyperventilation, correlated with hyperventilation induced haemodynamic changes and exercise test results and assessed the effect on them of age, gender, smoking and hypertension. Prolonged hyperventilation (overbreathing at least 30 respirations/min for 5 min and 10 min recovery) was performed in 474 healthy volunteers (269 men, 205 women) 42.6 +/- 13.5 years old. The electrocardiogram was analysed for transient ST depression or T-wave inversion. Repolarization abnormalities were observed in 72 subjects, 47 men (17.5%) and 25 women (12.2%). Age, gender, smoking and hypertension did not influence the overall incidence of repolarization abnormalities. ST depression was more frequently observed in women (4.4 vs 0.7%, P < 0.01), while T wave inversion from negative to positive was more frequent in men (8.9 vs 2.4%, P < 0.006). All subjects with ST depression were non-smokers (4.1% of the non-smokers, P < 0.003 compared to smokers). Repolarization abnormalities occurred usually (80.5%), but not exclusively, within the first hyperventilation minute. Subjects with repolarization abnormalities developed higher heart rate change with hyperventilation than those without repolarization abnormalities (29.2 +/- 13.1 vs 24.2 +/- 12.7, P < 0.002). A positive exercise test was observed in 45.4% of subjects with hyperventilation induced ST depression but only in 13.1% of subjects with T-wave changes, P < 0.02. Repolarization abnormalities are not uncommon during prolonged hyperventilation. Hear rate change affects the occurrence of repolarization abnormalities, while gender and smoking influence the type of repolarization abnormalities. ST depression but not T-wave inversion during hyperventilation is associated with a positive exercise test. Increased understanding about hyperventilation-induced repolarization abnormalities could affect use of the method in the clinic, either as a provocation test or as a complement to the interpretation of the exercise test.

Coronary artery calcium detected by digital fluoroscopy and risk factors in healthy subjects.

Coronary artery calcium detected by digital fluoroscopy is closely associated with known risk factors of coronary artery disease in asymptomatic low-risk populations. Even in the absence of significant luminal narrowing, this may not be an innocent finding, and subjects with coronary calcium may be at greater risk for developing obstruction and clinical disease.

Hemodynamic response to hyperventilation test in healthy volunteers.

Hyperventilation is well known to affect the electrocardiogram (ECG) in subjects without heart disease and produce spasm in patients with variant angina. The autonomic nervous system is thought to play a significant role in these effects. However, the normal hemodynamic response to hyperventilation is not well defined. We subjected 369 healthy volunteers (200 men, 169 women) to prolonged hyperventilation (30 respirations for 5 min and 10 min recovery) under continuous ECG monitoring and to exercise testing. Heart rate (HR), systolic and diastolic blood pressures (SBP, DBP) and rate-pressure product were recorded. Hyperventilation resulted in an immediate (within the first min), significant increase in HR by 27.4%, a further small increase at min 2 of hyperventilation, and a subsequent small decrease in HR at mins 3-5. An immediate drop of HR by 20.1% was observed with discontinuation of hyperventilation. Apart from a slightly higher HR increase in men, a similar pattern of HR changes was found in both genders. On multivariate analysis, younger age, absence of smoking, and male gender were associated with a higher HR increase with hyperventilation (p < 0.0001, p < 0.0001, and p < 0.001, respectively). SBP and DBP increased with hyperventilation, with their highest value at min 5 of hyperventilation and a subsequent drop to baseline levels. Age and gender did not affect the degree and pattern of BP changes. Absence of smoking and the presence of hypertension were associated with a higher SBP with hyperventilation (p < 0.003 and p < 0.007). The rate-pressure product increased by 43.6% with hyperventilation, a change that was only 19.1% of the respective rate-pressure product observed with exercise. Hyperventilation results in significant HR and BP increases, changes that are influenced by age, gender, smoking, and hypertension. Our study could serve as a standard for comparison of the hyperventilation effects in different disease states.