[Hypocalcemia causing heart failure]. / Hipocalcemia causando insuficiência cardíaca.

A 39-year-old female patient with refractory heart failure has been studied. On February, 1982 she was submitted to right lobar thyroidectomy for remotion of the left thyroid lobe. Following the surgery, she had signs of hypocalcemia and the diagnosis of secondary hypoparathyroidism and heart failure had been made. Seven months after she had acute pulmonary edema, cardiomegaly III (cardiothoracic index = 0.58) with predominant left atrial and left ventricular hypertrophy, which were confirmed by echocardiogram (ECO). The ECO also demonstrated low contractility of the left ventricle. The QT interval was increased on the electrocardiogram (QTc = 0.50 s), the calcium was 5.0 mg/dl with calciuria of 28 mg/day; phosphatemia was 4.8 mg/dl and phosphaturia of 214 mg/day. The level of thyroid hormones (T3 and T4) were in the normal ranges despite the TSH was increased in the beginning of the disease. She was first treated with digitalis, diuretic and vasodilator drugs, thyroid hormone and oral calcium. She had progressive hemodynamic improvement when higher doses of calcium were given with D3 vitamin. The most significant result of this treatment was reduction of the heart size that come back to normal. At the present time patient is treated with thyroid hormone, calcium and D3 vitamin only.

[Evaluation of syncope in patients with chronic Chagas heart disease]. / Avaliação da síncope em pacientes com cardiopatia chagásica crônica.

PURPOSE: To evaluate causes of syncope in patients with Chagas' disease and intraventricular conduction disturbances. METHODS: Nine patients have been studied, being seven males. Average of 49 years. The studied consisted of His Bundle electrogram, determination of Wenckebach period (WP), sinus node recovery time (SNRT), atrial stability and programmed ventricular stimulation (PVS). RESULTS: Monomorphic ventricular tachycardia (VT) was induced in five patients (55.5%), WP depression was observed in three cases, H-V interval prolongation occurred in three cases and the SNRT was normal in hall patients. In one case the electrophysiological study was completely normal. Among five patients with induced VT, with a mean follow-up period of seven months, one died suddenly, three became asymptomatic with antiarrhythmic drugs and one went on a non pharmacological therapy. In the other four patients with a mean follow-up period of 21 months, three are asymptomatic and one presents occasional dizziness (patient with a normal study). Among the patients with VT four presented recurrent syncope while in the group of patients without VT (four patients) all had only one syncopal episode. CONCLUSION: Patients with intraventricular disturbances, Chagas' disease and syncope, VT may be responsible for the symptoms in approximately 44% of cases. The PVS must be considered as a routine in the investigation of these patients.

[Significance of prolonged PR interval in patients with His bundle branch block, bifascicular type]. / Significado do intervalo PR prolongado em pacientes com bloqueio dos ramos do feixe de His do tipo bifascicular.

PURPOSE: Evaluation of the prolonged PR interval and its predictive value for trifascicular block in individuals with bifascicular His bundle branch block. PATIENTS AND METHODS: 55 patients, 36 male and 19 female aged 57 + 15.8 years with bifascicular bundle branch block type have been studied. 11 cases had complete left bundle branch block and 44 cases had complete right bundle branch block with left anterior and superior division block. His bundle electrogram and atrial stimulation were performed in all patients. The atrial stimulation rate originating the Wenckebach phenomenon (SP) of the A-V conduction, and the A-H and H-V intervals were compared with the PR interval of the surface electrocardiogram. Patients were divided into three groups according to the PR interval: group I, Pr less than 200 ms, group II, PR between 190-280 ms and group III, PR greater than or equal to 280 ms. RESULTS: There was not linear correlation between the PR interval and WP in the three groups. There was a weak linear ascending correlation between the PR and A-H intervals in groups I and II (r + 0.59 and + + 0.43, respectively) and there was a descending correlation in the group III (r. - 0.64, P less than 0.05). In relation to the H-V interval there was not linear correlation with the PR interval in groups I and II, but there was a good ascending linear correlation in the group III (r 0.84, P less than 0.01). The incidence of prolonged A-H and H-V intervals increased as the PR interval was larger. CONCLUSION: The prolonged PR interval with bifascicular bundle branch block means, in the majority of cases, diffuse damage of the conduction system involving the A-V node and the infranodal region; starting from 280 ms, the delayed PR interval suggests involvement predominantly below the A-V node: to a higher PR interval corresponds a higher H-V interval and also, to a relatively shortest A-H interval.