Natriuretic peptide and echocardiography after operation of atrial septal defect.

Patients benefit from surgical seclusion of atrial septal defect but have excessive cardiovascular morbidity after the operation. We evaluated haemodynamics and looked for abnormalities of cardiac structures and function late after surgical seclusion of the defect. Serum N-terminal natriuretic peptide measurement and transthoracic and transoesophageal echocardiography were performed in 61 patients aged 43+/-15 years (mean+/-standard deviation) 21+/-5 years after surgery. The findings were compared with 67 control subjects. The patients had higher serum N-terminal atrial natriuretic peptide concentration than the control subjects (0.40+/-0.32 vs. 0.24+/-0.12 nmol/l, P=0.0001). Peptide levels correlated with current age (P=0.0001) and age at operation (P=0.0014), but not with age in the control subjects. In the patients, echocardiography measurements of cardiac dimensions correlated with hormone levels (atrial natriuretic peptide concentration with left atrial end-systolic diameter (P=0.042), left ventricular end-diastolic (P=0.021) and end-systolic diameter (P=0.042). There were only 10 patients (16%) without any abnormality in echocardiography. Their peptide concentration was 0.25+/-0.18 nmol/l (P=not significant compared to the control subjects). The association between increasing N-terminal atrial peptide levels and operation age together with echocardiography findings support the clinical consensus of treating atrial septal defect patients in their childhood and adolescence.

Thyroid hormone substitution therapy rapidly enhances left-ventricular diastolic function in hypothyroid patients.

OBJECTIVE: Alterations in thyroid status may lead to changes in both systolic and diastolic function of the heart. Pulsed Doppler echocardiography is a reliable non-invasive means of assessing left-ventricular (LV) diastolic function. The aim of the present study was to evaluate LV diastolic function in patients with primary hypothyroidism receiving thyroxine therapy. METHODS: Twelve patients (all females, mean age 47 +/- 17, range 16-69 years) with primary hypothyroidism were studied by pulsed Doppler echocardiography. The first examination was made before the start of thyroxine substitution and the second at 37-68 (mean 53 +/- 10) days after commencing thyroxine treatment (mean dose 136 +/- 22 microg/day). RESULTS: During thyroxine substitution therapy, the hypothyroid patients became clinically euthyroid and serum T4 increased from 51 +/- 21 to 119 +/- 24 nmol/l; TSH decreased from 50.4 +/- 55.3 to 1.2 +/- 1.5 mU/l. During therapy, heart rate increased from 61 +/- 8 to 68 +/- 10 (p = 0.05). The LV posterior wall (7.8 +/- 1.0 mm) and interventricular septum thickness (8.0 +/- 1.4 mm) were significantly greater in hypothyroid patients than in the control subjects (6.4 +/- 1.0 mm, p = 0.007 and 6.8 +/- 1.0 mm, p = 0.04, respectively). There was no significant change in LV dimensions and wall thickness during follow-up. E/A(max) increased significantly during treatment (from 1.679 +/- 0.432 to 1.947 +/- 0.335, p = 0.006). The isovolumic relaxation time shortened significantly (from 88 +/- 23 ms to 75 +/- 24 ms, p = 0.005). CONCLUSIONS: The present study shows that LV diastolic function as assessed by pulsed Doppler echocardiography in hypothyroid patients is enhanced by thyroxine therapy during a rather short follow-up period.

Serum N-terminal atrial natriuretic peptide in adult patients late after surgical repair of atrial septal defect.

BACKGROUND: The purpose of surgical closure of atrial septal defect (ASD) is to relieve the cardiovascular system from a haemodynamic burden. Excessive amounts of atrial peptides are released in congestive heart failure, valvular diseases and congenital heart diseases. AIMS: To examine whether patients after surgical repair of ASD have higher concentrations of N-terminal atrial natriuretic peptide (ANP-N) than age-, sex- and body mass index (BMI)-matched control subjects. METHODS: Medical history, physical examination, standard 12-lead electrocardiogram, and ANP-N concentrations were obtained in 65 adult patients operated for ASD at the age of 21+/-13 years (mean+/-standard deviation), 21+/-6 years after surgical closure of ASD. Sixty-seven healthy subjects matched for age, sex and BMI served as controls. RESULTS: In the patients serum ANP-N was higher than in the control subjects 0.41+/-0.32 nmol/l, median 0.31 nmol/l, interquartile range (IQR) 0.21-0.49 nmol/l vs. 0.24+/-0.12 nmol/l, median 0.23 nmol/l, IQR 0.17-0.29 nmol/l, (P=0.0003). Patients with concomitant diseases had higher ANP-N concentrations (0.51+/-0.39 nmol/l, median 0.34, IQR 0.26-0.73 nmol/l) than ASD patients without any history or signs of disease (0.28+/-0.16 nmol/l, median 0.27, IQR 0.17-0.40 nmol/l, P=0.01). The 'healthy' ASD patients had higher hormone concentrations than age-, sex- and BMI-matched control subjects (0.28+/-0.16 median 0.27 nmol/l, IQR 0. 17-0.40 nmol/l and 0.21+/-0.07 nmol/l, median 0.20 nmol/l, IQR 0. 15-0.27 nmol/l, P=0.01). Multiple stepwise linear regression analysis showed that age at operation was strongly associated with the post-operative ANP-N concentration (r(2)=0.25, P=0.0002). CONCLUSION: ASD patients have higher ANP-N concentrations late after surgical repair. Hormone levels correlate with age at operation. Our finding supports the clinical praxis of operating on these patients in their childhood and adolescence.

Late postoperative follow-up of ostium secundum defect.

AIM: To perform late postoperative assessment of patients with ostium secundum defect. METHODS: We studied 45 patients 22+/-4 years after operation using clinical examination, transthoracic and transoesophageal echocardiography and electrocardiography. RESULTS: Patients operated on at 24 years reported dyspnoea upon exercise. Mitral regurgitation occurred more frequently in patients operated on at 24 years (29% vs 69%, P<0.05). Tricuspid regurgitation was mild in 20 patients (45%). There was an inter-atrial communication in 13 patients (28%). Eighteen patients (40%) had an enlarged right ventricular diameter. A tricuspid regurgitation gradient >30 mmHg was measured in seven patients (16%). Seventeen patients (38%) had significant electrocardiographic abnormalities. CONCLUSIONS: Late after uncomplicated seclusion of ostium secundum defect patients operated at >24 years have more symptoms than those operated on at an earlier age. Residual lesions are common. Mitral regurgitation is more frequent in patients operated on at >24 years. Our findings support the clinical consensus of operating on these patients in their childhood and adolescence.

Calcium infusion and left ventricular diastolic function in patients with chronic renal failure.

BACKGROUND: Left ventricular (LV) function is sensitive to disorders in calcium metabolism. Most previous reports have focused on the effects of calcium on systolic performance. We studied the acute effect of calcium infusion on LV diastolic function in patients with moderate to severe chronic renal failure (CRF) and secondary hyperparathyroidism (SHP). METHODS: We infused calcium gluconate at a constant rate of 45 mumol/kg/h to 14 patients with severe to moderate CRF and SHP. Our aim was to reach slightly supranormal levels of serum ionized calcium (1.35-1.45 mmol/l). LV diastolic function was assessed by pulsed Doppler echocardiography before and after the calcium infusion. The echocardiographic indices were compared to those of 14 age- and sex-matched healthy controls. RESULTS: Before calcium infusion the patients had significantly greater LV dimensions than the controls, but there was no differences in the diastolic indices. During calcium infusion, serum ionized calcium increased from 1.18 +/- 0.03 to 1.40 +/- 0.03 mmol/l (P < 0.0001) and plasma intact PTH decreased from 38.6 +/- 5.6 to 9.0 +/- 2.2 pmol/l (P < 0.0001). Calcium infusion did not affect the LV dimensions or fractional shortening. The peak early diastolic velocity (Emax) decreased and peak late diastolic velocity (Amax) increased, and their relationship decreased significantly (1.552 +/- 0.586 vs 1.414 +/- 0.535 m/s, P = 0.03). These changes reflect impairment of LV diastolic function. CONCLUSIONS: Induction of acute hypercalcaemia by calcium infusion impairs LV diastolic function in patients with CRF and SHP.

Fatal respiratory tract diphtheria apparently caused by nontoxigenic strains of Corynebacterium diphtheriae.

A major diphtheria epidemic affecting the whole population of St. Petersburg started in 1990. During the period of 1991 to 1995, 4600 patients with clinical respiratory tract diphtheria were treated in Botkin's Hospital. From 112 (2.4%) of these patients only a nontoxigenic strain of Corynebacterium diphtheriae was isolated. Three patients with this strain who were suffering from clinical disease consistent with classical toxic diphtheria died. All had myocarditis, two had asphyxia due to membrane formation in the lower respiratory tract, and one had severe polyneuritis. In two patients the causative agent was of the biotype mitis and in the third intermedius, whereas the prevailing epidemic strain was of the biotype gravis. As the clinical presentation of the disease in the three patients who died was typical of toxic diphtheria, it is considered likely that the immunodiffusion test for toxin production in vitro may fail to detect strains of Corynebacterium diphtheriae producing toxin in vivo.

Echocardiographic follow-up of diphtheric myocarditis.

We report the first case of diphtheric myocarditis documented by serial electrocardiography and echocardiography. The electrocardiographic changes preceded the contraction abnormalities by 3 weeks. During a prolonged neurologic disease with extensive polyneuropathy, the patient had only subtle clinical signs of myocarditis. In patients with diphtheria, electrocardiographic changes may warrant repetitive echocardiographic examinations.

Single right coronary artery assessed by contrast angiography and transoesophageal echocardiography.

Contrast angiography is the gold standard for the assessment of the site and severity of coronary artery narrowing. Transoesophageal echocardiography is recognized as a feasible technique in assessing coronary artery anomalies. Our patient had arteriosclerotic narrowing in a single right coronary artery with poor distal opacification during contrast injection. Combining transoesophageal echocardiography with contrast angiography helped us in visualizing a surgically accessible vessel on the anterior wall of the left ventricle.

Color Doppler myocardial imaging: a new technique for the assessment of myocardial function.

Color Doppler myocardial imaging is a new technique that has been developed specifically to allow color Doppler imaging of myocardial wall motion rather than blood pool imaging. Such a technique has the potential to interrogate velocities, accelerations, and Doppler signal strength within the myocardial wall. Moreover, the concomitant enhancement of the myocardial Doppler signal after an intravenous injection of a transpulmonary echocardiographic contrast agent could permit the noninvasive assessment of regional myocardial perfusion. Thus this new imaging modality could be a valuable adjunct to the ultrasound assessment of myocardial ischemia.