The effect of diltiazem, a calcium channel-blocking drug, on cardiac rate and rhythm in hyperthyroid patients.

Tachycardia and tachyarrhythmias are frequent in patients with thyrotoxicosis, especially in the elderly. Since myocardial calcium uptake is increased in thyrotoxic rats, the efficacy of the calcium channel-blocking drug diltiazem in decreasing heart rate and the incidence of arrhythmias was evaluated in 11 hyperthyroid patients. All patients were studied with a 24-hour Holter monitor prior to the beginning of sole diltiazem therapy (120 mg given every eight hours), on the tenth day of therapy, and five days after therapy was discontinued. Heart rate significantly decreased by 17% during diltiazem treatment (96.5 +/- 3.7 systoles/min vs 79.9 +/- 3.2 systoles/min [mean +/- SE]) and returned to baseline values five days after the therapy was discontinued (100.7 +/- 3.4 systoles/min). Similarly, the number of premature ventricular extrasystoles per hour was significantly decreased (18 +/- 7 vs 2 +/- 1). In three patients, asymptomatic bouts of supraventricular tachycardia, paroxysmal atrial fibrillation, or ventricular tachycardia disappeared during diltiazem therapy. These findings suggest that calcium-blocking drugs may be extremely useful as adjunctive therapy for thyrotoxicosis in the presence of angina, congestive failure, and tachyarrhythmias.

Sinus node function in hyperthyroid patients.

We have studied the electrophysiology of the sinus node and the role of the autonomic nervous system on sinus node function in 8 thyrotoxic patients of both sexes, 37.5 +/- 4.3 (mean +/- SE) yr old. The resting heart rate (RHR), the sino-atrial conduction time (SACT), and the sinus node recovery time (SNRT) were measured in the untreated condition (basal), after sympathetic blockade with propranolol 0.2 mg/kg body weight (BW) i.v. infusion, and after complete autonomic blockade with the additional administration of atropine 0.04 mg/kg BW i.v. bolus. 1) In the thyrotoxic patients the RHR was higher [117 +/- 6 beats per min (bpm)] than in 20 normal subjects (73 +/- 1 bpm, P less than 0.001), whereas the SACT and SNRT values were not different. 2) After sympathetic blockade with propranolol, the RHR decrement and SACT increase were greater in the hyperthyroid patients than in normal subjects, whereas there was no difference in SNRT values between the two groups. 3) In the thyrotoxic patients the complete autonomic blockade reestablished the electrophysiological parameters to values similar to those observed in basal condition. In conclusion, in thyrotoxic patients the intrinsic activity of the sinus node is increased. It appears that this is a direct consequence of thyroid hormone excess, rather than an effect of extrinsic influences exerted by the autonomic nervous system on sinus node activity.

Comparison of dilevalol and enalapril administered once daily for mild hypertension.

This was a multicenter, randomized, double-blind, parallel-group study of the efficacy and safety of dilevalol, 200 mg (n = 86), compared with enalapril, 20 mg (n = 92), administered once daily to patients with mild hypertension. Three weeks of placebo washout were followed by 4 weeks of comparative treatment. Beginning with the first week of treatment, both drugs substantially decreased blood pressure from baselines of approximately 160/100 mm Hg. Decreases in systolic pressure were comparable throughout treatment, but dilevalol tended to have a greater effect on diastolic pressure. At the end of double-blind treatment, average decreases in blood pressure with dilevalol and enalapril were 16/13 and 16/11 mm Hg supine and 15/13 and 15/10 mm Hg standing (p = 0.03 for between-group comparisons of standing diastolic pressure). More dilevalol- than enalapril-treated patients achieved a diastolic pressure less than 90 mm Hg; 73 vs 55% (p = 0.02) supine, and 69 vs 43% (p less than 0.01) standing. The safety profiles of the 2 drugs were comparable. The incidence of adverse effects was low, and few patients discontinued treatment. Headache and gastrointestinal discomfort were reported in both groups. Average postural changes in blood pressure were similar to baseline. Electrocardiographic changes were rare and not treatment related. Changes in laboratory test results were minor. Heart rate decreased modestly with dilevalol relative to enalapril (6 vs 2 to 3 beats/min; p less than 0.01), but no bradycardia was observed.

[Effects of hypertrophy on cardiac systolic and diastolic performance in athletes with mild hypertension]. / Effetti dell'ipertrofia sulla performance cardiaca sistolica e diastolica in atleti con ipertensione lieve.

Aims of the study has been the evaluation of morphological and functional aspects of left ventricle in subjects undergoing mild hypertension and sport adaptation effects. These evaluations have been carried out by Echo-Doppler both at rest and during sharp increase in after load induced by isometric stress. Together with the morphological parameters represented by mass index and by radius to thickness ratio, we have studied stroke volume and transmitral flow pattern assessing the maximum flow velocity during rapid filling phase (E), during atrial contraction phase (A) and their ratio (E/A). We have studied 31 male subjects from 39 to 60 (average 47) exercising twice or three times a week (in the main, aerobic sports such as road cycling). They were subdivided into two groups, the first included 16 subjects with mild hypertension (AP = 155 +/- 9/97 +/- 5 mmHg) the second included 15 normotensive subjects without known pathologies, comparable for age and body surface (AP = 125 +/- 15/77 +/- 10 mmHg). Hypertensive subjects exercising regularly, showed a mass index (164 +/- 42 g/m2) significantly higher than the controls (139 +/- 35 g/m2, P less than 0.01) but they ke a normal filling pattern at rest and similar stroke volume values. During isometric exercise instead, the velocities of E and A waves showed a different trend in the two groups with a higher reduction in E/A ratio in hypertensive subjects. The per cent decrease in this ratio turned out to be 15% in the control group and 33% in hypertensive subjects (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Cardiocirculatory adaptations during the initial phases of pregnancy. An echo-Doppler assessment]. / Adattamenti cardiocircolatori durante le fasi iniziali della gravidanza. Valutazione eco-Doppler.

During pregnancy the cardiovascular apparatus meets an important process of morphofunctional adjustment. However the very moment when this happens is not very well known. We observed thirty patients during the various GIFT phases (Gamete Intrafallopian Transfer) that consists in the intratubal transfer of male and female gametes and that represents also an ideal model for the study of pregnancy in the early phases. With echo-Doppler technique morphological and functional parameters of the left ventricle have been evaluated and at the same time estradiol and progesterone blood variations have been determined. In all the thirty patients to the increase of E2 corresponds a significative increment of telediastolic (Dd) and telesystolic (Ds) diameter and of systolic index (SI) and cardiac index (CI). At the same time a significant reduction of mean arterial pressure and of the index of a systemic vascular resistance has been observed. These data say that the systolic flow increment is not due to an increase of the ejection fraction but to an increase of the diastolic filling. The utilised mechanism has nothing to do with inotropism but to the preload reserve according Starling principle. The increase of the systolic output is the almost unique cause of the cardiac capacity increment because there is only a light increase of heart rate. Those patients in which GIFT gave a positive results, these variations are sustained while in the group of those patients not pregnant one can see a rapid return to basic values of the various parameters (except the presence of a significative Dd increment) together with the reduction of plasmatic E2. In conclusion our work results say that significative cardiovascular adjustments are evident from the earliest pregnancy phases and that these changes one can related to E2 plasmatic variations.

[Effectiveness of depot diltiazem in stable effort angina: a double-blind study compared with placebo]. / Efficacia del diltiazem retard nell'angina stabile da sforzo: studio in doppio cieco in confronto a placebo.

AIM OF THE STUDY: The antianginal efficacy of slow-release (SR) Diltiazem and change in ergometric parameters during treatment were evaluated in patients with stable effort angina. METHODS: Forty eight patients with documented ischemic cardiopathy were studied. The study design was double blind randomised cross over versus placebo. After a 7 days run-in period of pharmacological washout, patients were randomised to treatment with diltiazem SR (120 mgs bid) or placebo for 1 week, followed by crossover of treatments. No concomitant antianginal therapy, except sublingual nitro-glycerine was allowed during the trial. Exercise tests were performed during the run-in period and at the end of each week of treatment. RESULTS: After diltiazem administration, exercise duration increased significantly in comparison with placebo (645.6 +/- 196.31 vs 563.9 +/- 244.52 s, p < 0.01). Similarly, time to onset of angina and time to ischemic threshold increased in comparison to placebo (603.78 +/- 198.50 vs 459.69 +/- 239.40 s, p < 0.01 and 576.06 +/- 208.88 vs 463.16 +/- 246.12 s, p < 0.01 respectively). No significant changes in heart rate, blood pressure and double product at ischemic threshold and peak exercise were detected. CONCLUSIONS: SR-diltiazem is effective and well tolerated in the treatment of patients with stable angina.

[Malfunctioning of the Meadox bioprosthesis placed in mitral position. Description of 2 clinical cases]. / Malfunzionamento della bioprotesi di Meadox posizionata in sede mitralica. Descrizione di due casi clinici.

The Meadox valve, made up by a single bovine pericardial leaflet fixed in glutaraldehyde, is a "new-generation" bio-prostheses. In two patients those bio-prostheses revealed early malfunction with abnormal stretching of the valvular tissue. In both cases the beginning symptom was a strong fremitus caused by the vibration, during systole, of valvular leaflet. In the first case mechanical solicitation onsed partial laceration of valvular leaflet with subsequent regurgitation into the left atrium and cardiac failure. In both cases, the evaluation by Doppler Echocardiography and polygraphic examination, allowed the diagnose of malfunction which was confirmed at surgery. The replacement of a new prosthesis was successful in both cases.

[Acute myocardial infarction in pregnancy in a patient with pseudoaneurysm of the left main coronary artery]. / Infarto miocardico acuto in gravidanza, in paziente con pseudoaneurisma del tronco comune della coronaria sinstra.

Myocardial infarction during pregnancy is a rare event and it can be associated both with obstructive coronary artery disease and with functional conditions such as vasospasm. We report a 28-year-old woman without coronary artery disease risk factors, who suffered a Q infarction at 38th week of gestation, complicated by ventricular fibrillation. A healthy child was delivered by cesarean section and the woman made a full recovery. A coronary pseudoaneurysm was detected angiographically, suggesting an initial spontaneous coronary artery dissection followed by ectatic evolution. Coronary dissection associated with coronary vasospasm should be kept into account as etiopathogenetyc mechanisms of acute myocardial infarction.

[Enzymatic assessment of the area of necrosis. I. Diagnosis and quantitative evaluation of acute myocardial infarct by means of MB creatine kinase isoenzyme. Comparison with deduced from creatine kinase activity]. / Quantizzazione enzimatica dell'area di necrosi. I) Diagnosi e valutazione quantitativa dell'infarto miocardico acuto mediante l'isoenzima MBCK. Confronto con i risultati dedotti dall'attività CK.

On the purpose of specifying more and more the peculiarity of the isoenzymes MBCK in regard to enzyme CK, in the diagnosis as well as in the quantitative evaluation of myocardial infarction, we examined 34 patients hospitalized in U.C.I.C. The curves of the MBCK and CK were obtained through samples taken every 2-3 hours still the 12th hour, after the enzymatic concentration have exceeded the normal level and successively every 4 hours till the enzymatic activity regains its limits. The values of I.S.MBCK and I.S.CK were compared and we obtained two correlations based on the enteric work (r = 0.79) or on selected cases (r = 0.96). We conclude, for the major practicality and usefulness of measurement of MBCK in the evaluation of size, because this measurement can be obtained on the total enumeration of cases of myocardial infarction, not takine into consideration all those factors which could produce an increase of CK; moreover the MBCK is able to show the extension of myocardial infarction that would not be detectable with CK.

[Changes induced by temporary compression of A-V fistula on some polygraphic parameters in chronic hemodialysis patients]. / Variazioni indotte dalla temporanea chiusura della fistola A-V su alcuni parametri poligrafici in pazienti cronici dializzati.

In order to evaluate the influence of an arterio-venous fistula on cardiac function, a non-invasive study was conducted in thirty-three patients before and during compression of the fistula. Significant changes of PEP/LVET ratio and ITD were observed by means of such a technique only in patients with proximal (forearm) fistula; on the contrary no significant change were noted in those with distal (radiocephalic) a-v fistula. A systolic apical or precordial murmur, that was present in the control state in ten patients, was abolished or reduced in intensity in seven of them. Therefore suppression of blood flow through the shunt appears to affect the systolic time intervals in patients with proximal forearm fistula.

Diagnostic and prognostic value of vasodilator stress echocardiography in asymptomatic Type 2 diabetic patients with positive exercise thallium scintigraphy: a pilot study.

AIM: To assess the diagnostic and prognostic value of vasodilator stress echocardiography in Type 2 diabetic patients with positive exercise perfusion scintigraphy. METHODS: Of an initial cohort of 50 asymptomatic Type 2 diabetic patients undergoing exercise single photon emission computed tomography (SPECT) thallium scintigraphy, 24 had a positive thallium scan, with a reversible perfusion defect. All these 24 underwent high dose (up to 0.84 mg/kg in 10 min) dipyridamole echocardiography and coronary angiography independently of stress echocardiography results. All patients were then followed for 61+/-22 months. RESULTS: Coronary angiography showed normal coronary arteries in 11 patients and significant (> 50% visually assessed diameter reduction in a major vessel) coronary artery disease in 13. Stress echocardiography showed 92% sensitivity and 100% specificity for non-invasive detection of coronary artery disease. During follow-up, five patients experienced cardiac events: heart failure in one, angina with subsequent revascularization in two, and myocardial infarction in two. Event-free survival was 100% in the 12 patients with negative and 58% in the 12 patients with positive stress echocardiography (P = 0.08 by Mantel-Cox test). CONCLUSIONS: In asymptomatic Type 2 diabetic patients with stress-induced perfusion defects, vasodilator stress echocardiography is an excellent diagnostic and prognostic tool proven with long-term follow-up.

[AI-CARE: a multicentric study on unstable angina. Methodology and preliminary data of a project on the improvement of health care quality in Emilia-Romagna]. / AI-CARE: indagine policentrica sull'angina instabile. Metodologia e dati epidemiologici relativi ad un progetto sulla qualità delle cure in Emilia-Romagna.

BACKGROUND: Recent Italian legislative directives have focused on lowering health-service costs and improving the quality of health care. The AI-CARE study on unstable angina represents the initial observational step in a survey on health-care quality in the Italian region Emilia-Romagna. AIM OF THE STUDY: This study was performed to identify the processes usually involved in the management of patients with unstable angina admitted to a regional cardiology department. The consumption of health service resources and the clinical events related to angina were evaluated. METHODS: AI-CARE is an observational, descriptive and prospective study. Between 15/3/95 and 15/6/95, the patients admitted consecutively to 25 cardiology units for unstable angina, as diagnosed on a clinical basis, were enrolled in the study. A six-week follow-up was provided. The data regarding demographics, history, entry electrocardiogram, symptoms, examinations, treatment and outcome were recorded on a detailed personal questionnaire. The participating centers have been divided according to complexity of organization: 18 with intensive care unit as level I, five with hemodynamic laboratory as level II and two with cardiosurgery as level III. Mortality, myocardial infarction, revascularization procedures and readmissions for angina were considered clinical events. RESULTS: We recruited 463 patients. At discharge, 411 patients were affected with unstable angina while other 40 developed non-Q wave infarctions. The final study population comprised 451 patients. The mean age was 68 years (range 61-76). There were 316 men (69%, mean age 68) and 135 women (mean age 72). All 451 patients were stratified according to the Braunwald classification: IIIB in 66.9%, IIIC in 9.9%, IB in 9.9%. Mean hospital stay was 10 +/- 6 days, while mean stay in intensive care units was 4.3 +/- 2.9 days. Medical treatment included antiplatelet agents (89%), nitrates i.v. (81%), nitrates per os (86%), heparin (55%) and beta-blockers (47%). The most common non-invasive test performed was echocardiogram (70% of patients), Holter ECG and exercise stress testing (19%). Selective coronary arteriography was performed in 50% of patients (23% during the first 10 days). Additionally, 32% of patients underwent revascularization. During follow-up, ten patients (2.21%) had a myocardial infarction, nine patients (1.99%) died and 49 patients (10.8%) were readmitted for angina. CONCLUSIONS: This study indicates that in spite of the poor use of diagnostic procedures (especially coronary arteriography) and myocardial revascularization, mortality and morbidity were relatively low. Our data are similar to the results of the recent Italian EARISA study but differ greatly from the results of foreign studies. Consequently, further observation of our study population is needed.