European journal of cardiology最新文献

The effect of hyperbaric oxygen (HBO) on infarct size associated with myocardial infarction remains uncertain. Accordingly, the present study was performed in 46 conscious dogs with experimental infarction to determine the effect of HBO on enzymatic estimates of infarct size. Since HBO may affect plasma creatine kinase (CK) release or disappearance, parameters used to calculate enzymatic estimates of infarct size from plasma CK, we assessed infarct size by directly measuring myocardial CK depletion. Twenty-three animals were given HBO (2 atm of pressure) for 3 h immediately after coronary occlusion and results of infarct size compared to those in 23 dogs with occlusion who remained in room air. In 10 other animals CK release was measured after coronary occlusion in 5 controls and compared to 5 treated. In 5 normal animals the CK disappearance rate of purified canine CK was determined before and after HBO. Infarct size was determined 24 h after coronary occlusion and in the treated animals averaged 25.4 +/- 1.3% of LV (mean +/- SEM), and being similar to controls (26.7 +/- 1.4, P greater than 0.25). The plasma CK disappearance rate before and after HBO was the same being 0.0072 +/- 0.0022 (min-1) and 0.0073 +/- 0.0021, respectively. Total CK released into the plasma was also the same in treated and controls (2232 +/- 210 IU and 2011 +/- 232), as was the ratio of CK released to that depleted from the myocardium (0.15 +/- 2% vs 0.15 +/- 3%). Our results indicate: (1) HBO does not reduce infarct size produced experimentally in the conscious dog; (2) HBO does not affect CK release or disappearance; and (3) estimates of infarct size by plasma CK remain valid despite administration of HBO.

Hydralazine (Apresoline) was used to increase heart rate in 21 patients (14 hypertensive and 7 normotensive) suffering from symptomatic sinus bradycardia (SSB). Patients were assessed clinically and by 24-h ECG analysis before and after tailored increasing doses of the drug. Heart rates measured were resting (basal) rate, minimum rate during sleep, maximal rate during the day, and mean rate during the 24-h period (from hourly strips). The longest sinus pause or period of sinus arrest (when present) was also measured. Hydralazine ameliorated symptoms and produced a 20% or greater increase in heart rate in just under two-thirds of the hypertensive and half of the normotensive patients. Blood pressure decreased slightly in hypertensive but not in normotensive patients, and there were no important side-effects. Hydralazine appears to be a useful and effective drug to increase heart rate in patients with SSB.

Cardiac programmed stimulation in the control of tachyarrhythmias offers encouraging prospectives. We describe two devices which utilize radiofrequency as a means of synchronization and stimulation and can be triggered by the patient himself when tachycardia occurs. In addition we introduce a third anti-tachycardia device, completely automatic, which can be used in cardiologic departments. The first device described permits critical stimulation and can be programmed to deliver a single or double synchronized impulse. The second device, which utilizes the same implanted unit and electrode as used for critical stimulation, when activated searches the tachycardia interruption zone by scanning. The third device, based on the same principles, has a rate discriminator that activates the scanning stimulation. We treated 12 patients: 8 suffering from paroxysmal supraventricular tachycardia (4 with Wolff--Parkinson--White syndrome, 2 with intranodal reentry, 2 with brady--tachy syndrome); 2 patients with ventricular recurrent tachycardia; 1 with atrial flutter; and another with iterative junctional tachycardia. The follow-up varied for every patient from 6 yr to 3 mth.

A comparative blood pressure and sodium excretion were higher in Korea than in Belgium. By multiple regression and covariance analysis an independent positive association between sodium and blood pressure and a negative correlation between potassium and blood pressure were found in some population subgroups and in the total population studied in Korea. In Belgium a positive association between sodium and blood pressure was found when higher powers of age, height, weight and sodium were included in the analysis. The independent influence of sodium on blood pressure was relatively small, amounting to about 2 mm Hg of pressure rise for an increase in 24-h excretion of 100 mmol of sodium.

The possible harmful effect of physical activity on the extent of myocardial damage in patients with fresh myocardial infarction (AMI) has been a matter of debate. In this paper, serial determinations of serum creatine kinase (CK) isoenzymes are presented from 20 unselected patients with AMI, in 14 of them complicated by congestive heart failure or/and significant rhythm disturbances. During the acute phase, the cardiospecific MB-isoenzyme of CK in all patients rose above the upper reference limit of 30 U/l, the peak values ranging from 39 to 741, and returned to normal range within a few days. During the third week a maximal, symptom-limited exercise test was performed, with renewed serial determinations of CK-isoenzymes. Following the exercise an ST-segment deviation in the ECG was noted in 14 patients, anginal pain in 4, and a significant rise in serum CK--MM activity in 9 patients, whereas the CK--MB isoenzyme remained at zero level in all 20 patients. Thus, no evidence was found that even a maximal physical effort during the third week after AMI did cause any myocardial damage.