Alterations in circulating thyroid hormones and thyrotropin in euthyroid patients with Graves' disease after total thyroidectomy: comparison between responders and nonresponders to TSH-releasing hormone

Eleven euthyroid patients with severe exophthalmos of Graves' disease who had been treated with antithyroidal drugs for one to three years prior to total thyroidectomy were studied. All patients were clinically and biochemically euthyroid at the time of operation. According to their responses of TSH to TRH prior to operation, the patients were divided into two groups: (1) five responders and (2) six nonresponders. In group 1, serum TSH levels increased significantly on the third day after thyroidectomy (from 1.5 +/- 0.3 to 8.6 +/- 1.4 microU/mL: P less than 0.05); serum T4 concentrations decreased significantly and were in the hypothyroid range by the third day. In group 2, serum TSH levels rose from 0.5 +/- 0.01 to 3.2 +/- 0.5 microU/ml (P less than 0.05) on the ninth postoperative day; serum T4 concentrations decreased on the third day after operation but did not attain hypothyroid levels until the 12th day. Thus after total thyroidectomy the following are concluded: (1) serum TSH levels even in treated euthyroid patients with Graves' disease, rose more gradually in TRH-nonresponders in comparison with TRH responders; (2) the time when serum TSH elevation occurs is dependent upon serum concentrations of thyroid hormones (serum T3 and T4).     

Electrocardiographic criteria for differentiating aberrancy and ventricular extrasystole in chronic atrial fibrillation: validation by intracardiac recordings

Many electrocardiographic criteria have been proposed for the differentiation of ventricular extrasystole and supraventricular conduction with aberrancy in atrial fibrillation but the validity of these have not been confirmed by intracardiac studies. We recorded His bundle electrograms in nineteen patients (eleven men, eight women) referred for diagnosis of abnormal QRS complexes in the context of chronic atrial fibrillation. Of 1,068 wide QRS complexes analyzed, 91% proved to be of ventricular origin. Electrocardiographic criteria which were specific for ventricular extrasystole included: left bundle branch block morphology, right bundle branch block morphology with a monophasic R in lead V1 or an RS or QS pattern in lead V6, presence of a "compensatory pause", i.e., compensatory cycle (V2-V3) longer than the average cycle length of ten normally conducted beats preceding the abnormal complex (927 +/- 317 vs 780 +/- 199, mean +/- SD in msec. p less than 0.005), frontal QRS axis of the abnormal complex directed superiorly or to the right and the presence of a "short-long" cycle sequence. Right bundle branch morphology with a triphasic R in lead V1 or QRS pattern in V6 and concordant initial vector in lead V1 or in more than one ECG leads were very specific for supraventricular conduction with aberrancy. Analysis of coupling interval and Ashman's phenomenon, i.e., the long-short cycle sequence, were not specific for supraventricular conduction with aberrancy. We conclude that in digitalis-treated patients with chronic atrial fibrillation the majority of abnormal QRS complexes are of ventricular origin. The diagnosis of ventricular extrasystole or aberrancy can be made using a single ECG lead (V1) and applying a combination of easily applied criteria.     

Smooth muscle contraction bands in the media of coronary arteries: A postmortem marker of antemortem coronary spasm?

To date, no unequivocal morphologic markers have been described that would allow the diagnosis of coronary artery spasm to be made at autopsy. The coronary arteries of 63 adult patients without myocardial infarction were examined at autopsy, and the presence of medial smooth muscle contraction bands in these vessels was correlated with other vascular changes, myocardial pathologic changes and clinical history. These contraction bands have not been reported previously in human coronary arteries, but they were identified in experimental vascular spasm induced with catecholamines. It was found that 47 of the 63 cases were positive for contraction bands. As evidence of an antemortem process, there was a significant correlation between these changes and the presence of nonocclusive microthrombi, found in 25 cases. Contraction bands were also highly correlated with atherosclerotic plaque ruptures and mural plaque hemorrhages, which may be secondary to coronary spasm. In 78.7% of the cases positive for contraction bands, the cause of death was related to a diagnosis possibly associated with high catecholamine levels. On the basis of experimental evidence and the correlations identified in this study, coronary artery medial smooth muscle contraction bands may represent a postmortem marker of antemortem coronary spasm.     

Effects of verapamil and lidocaine in a canine model of sudden coronary death

The efficacy of verapamil and lidocaine for treating ischemia-induced arrhythmias was determined in a conscious canine model with a previous myocardial infarction remote from the ischemic area. Temporary (up to 5.5 minutes) occlusion of the circumflex coronary artery was made in eight conscious dogs that had sustained an anterior myocardial infarction 13 to 35 days previously. Each dog served as its own control. Ventricular arrhythmias were observed in 100% of control experiments but in only 25% of experiments after verapamil pretreatment at 0.4 mg/kg body weight. Repetitive ventricular complexes, defined as two or more consecutive ventricular complexes terminating spontaneously in sinus rhythm, were seen in 88% of control experiments and 13% of verapamil experiments, whereas ventricular fibrillation was seen in 6% of control experiments but in no verapamil experiment. Thus, verapamil abolished arrhythmias or reduced the grade of arrhythmias in all dogs. Six of the eight dogs were also tested with lidocaine pretreatment at one or two doses resulting in mean plasma levels of 3.8 +/- 2.0 micrograms/ml. Ventricular arrhythmias were seen in 92% of control experiments and 100% of lidocaine experiments. The incidence of ventricular fibrillation increased from 8% in control to 60% in lidocaine experiments. It is concluded that verapamil may prevent severe ischemia-induced arrhythmias after a recent myocardial infarction, whereas lidocaine may in some cases aggravate arrhythmias.     

Plasma lipoprotein abnormalities associated with acquired hepatic triglyceride lipase deficiency

Two enzymes, lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL), are released into human plasma after intravenous injection of heparin. LPL is the major enzyme responsible for initiating catabolism of chylomicrons and very-low-density lipoproteins (VLDL). The physiological role of HTGL is less certain. HTGL has been postulated to be an alternate enzyme to LPL in hydrolysis of triglyceride in VLDL and to be an important enzyme for removal of phospholipid from both low-density lipoproteins (LDL) and high-density lipoproteins (HDL). In this latter role, this enzyme would convert larger, lighter lipoprotein particles to smaller denser particles. HTGL deficiency has been found in severe liver disease and with a genetic deficiency of this enzyme. A unique patient is described with acquired hepatic triglyceride lipase deficiency and vitamin A intoxication. This patient developed hypercholesterolemia with an increase in both LDL and HDL. An increased proportion of lighter LDL (LDL1) and HDL (HDL2) was noted. In addition, after administration of heparin there was no shift in the distribution of apoE in plasma fractionated using a column containing 4% agarose. These findings are consistent with a postulated role of HTGL in metabolism of light LDL and HDL particles and some classes of apoE containing lipoproteins.     

Evaluation of dopaminergic tone in hyperprolactinemia. III. Thyroid-stimulating hormone response to metoclopramide in differential diagnosis and postoperative follow-up of prolactinoma patients

Recently, it has been shown that patients with a PRL-secreting pituitary adenoma have a greater thyroid stimulating hormone (TSH) release after dopamine (DA)-receptor blockade than normal subjects. We have compared the TSH and PRL responses to metoclopramide (MCP) in normal and postpartum lactating women with those in 28 patients with hyperprolactinemia of different origin. Patients with a PRL-secreting pituitary adenoma were also tested after transsphenoidal removal of the tumor in order to establish the prognostic value of this test in such patients. Following MCP administration, percent increases in plasma PRL levels were greater in normal female subjects than postpartum lactating women. Plasma TSH levels did not increase in postpartum women and had a modest increment in normal subjects. In patients with hypothalamic tumors and empty sella syndrome plasma PRL and TSH levels showed modest or no increases after MCP administration. In ten patients harboring a microprolactinoma, plasma TSH levels showed an exaggerated increment after DA-receptor blockade. Postoperatively, despite normal or borderline PRL levels in the immediate postoperative period, a TSH response to MCP was present (in five patients one to two weeks after the operation, and in five patients one to three years after the operation), suggesting an increased DA activity even in the absence of hyperprolactinemia. In conclusion, the TSH test can easily detect increased DA-activity in patients with a microprolactinoma both preoperatively and postoperatively. It is possible that some patients with increased DA-activity in presence of normal PRL levels and normal PRL responsiveness to stimulation will experience a recurrence of hyperprolactinemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evaluation of oral mexiletine therapy in the treatment of ventricular arrhythmias

The effect of oral mexiletine therapy on ventricular arrhythmias was evaluated in 58 patients in whom conventional drugs had been unsuccessful. Mean daily dose of mexiletine was 652 mg (range 250 to 1,500) and mean duration of therapy was 14.4 months (range 0.1 to 34.4). Mexiletine was associated with a decrease of 52% in total premature ventricular complexes in 24 hours compared with control (6,841 +/- 1,053 [SEM] versus 3,248 +/- 734, p less than 0.005) and 19 patients (36.5%) had a greater than 83% decrease in ventricular ectopic rhythm. The drug was discontinued in 6 of these 19 patients because 5 of them (26%) experienced side effects after a mean period of 29.6 weeks (range 0.83 to 63.2) and sudden death occurred in 1 patient (5%); this indicates effective suppression of ventricular ectopic rhythm without significant side effects in 13 (25%) of 52 patients during long-term therapy. Adjustment of drug dosage to achieve therapeutic blood levels resulted in an efficacy on ventricular ectopic rhythm similar to that obtained with the maximal tolerated dose. There was no correlation between drug dose and therapeutic effectiveness. Mexiletine was associated with a 48% decrease in episodes of ventricular tachycardia (345.5 versus 179.3/24 h) and 5 of 10 patients with a history of cardiac arrest remained free of symptomatic ventricular tachyarrhythmias for 14.8 months (range 3.7 to 24.3).(ABSTRACT TRUNCATED AT 250 WORDS)     

Adrenocorticosteroid therapy and gastroduodenal lesions

Gastroduodenoscopy was performed in 25 patients with various disorders, such as liver cirrhosis, nephrotic syndrome, and ulcerative colitis, to assess the effects of corticosteroids on the stomach and duodenum. The main criterion for entry into the trial was the absence of open ulcer, healed ulcer, erosion, or bleeding from the stomach or duodenum on pretreatment endoscopy performed within 48 hours before administration of corticosteroids. Endoscopy repeated at 2 to 4 weeks disclosed gastroduodenal lesions in 11 cases (44%)and no lesion in 14 cases (56%). The gastroduodenal lesions observed in 11 cases are as follows: one gastric ulcer (4.0%), six gastric erosions (24.0%), two gastroduodenal erosions (8.0%), and two duodenal erosions (8.0%). A lack of correlation between the patients' subjective complaints and endoscopic findings indicates the unreliability of patients' complaints and the importance of endoscopy in assessing gastroduodenal lesions. There were no differences in the total and average daily doses of corticosteroid between a group with gastric and/ or duodenal lesions and a group without such lesions. Corticosteroids may produce gastroduodenal lesions, regardless of the dose.     

Entrainment of circus movement tachycardia utilizing an accessory pathway with long retrograde conduction times during ventricular and atrial stimulation

An unusual case is presented in which a circus movement tachycardia incorporating an accessory pathway with long retrograde conduction time was transiently entrained. Overdrive high right atrial stimulation produced entrainment without atrial fusion since collision of anterograde and retrograde impulses took place within the accessory pathway. Tachycardia termination occurred when, at a faster pacing rate, an atrial impulse that collided in the accessory pathway was blocked at the atrioventricular (AV) node. In contrast, the entrainment seen during right ventricular apical stimulation was characterized by the occurrence of both fusion and collision within the ventricles. The tachycardia was terminated when a pure paced impulse that collided in the normal pathway was blocked in a retrograde direction in the accessory pathway. These data indicate that: 1) transient entrainment of this arrhythmia (circus movement tachycardia) can be identified by the classical criteria used to diagnose it, provided that fusion and collision occur within the ventricles; and 2) the accessory pathway is the weak link for tachycardia termination only during ventricular pacing since the AV node is the weak link during atrial stimulation.     

P-wave changes in obstructive and restrictive lung diseases

To evaluate the P wave changes in the electrocardiogram (ECG) in chronic lung diseases, we examined ECGs from twenty patients with interstitial pulmonary fibrosis (the FLD group) and twenty patients with chronic obstructive lung disease (fifteen with pulmonary emphysema and five with bronchial asthma, the COLD group). In the COLD group, the amplitude of P waves in leads II and III increased and the axis of the P wave shifted rightward. In the FLD group, however, these changes were not observed. Furthermore, the axis of the P wave exceeded +70 degrees in all the patients in the COLD group, and was less than +70 degrees for all the patients in the FLD group. The increased P wave terminal force in lead V1 was found in nine patients (45%) of the FLD group and in ten patients (50%) in the COLD group. We concluded that the rightward shift of the axis of the P wave was a characteristic of obstructive lung disease and that it was mainly caused by the overinflation of the lung. This P wave change was not observed in interstitial pulmonary fibrosis.