Biomedical subjects

N Treese

Publications and source records attributed to N Treese.

111 records · Page 7Linked to original sources

PubMedDate not supplied

Vulnerability of the right ventricle to cathodal, anodal, and bipolar stimulation at double diastolic threshold strength.

UNLABELLED: The repetitive ventricular response (RVR) to three stimulation techniques (bipolar, cathodal and anodal) was investigated in 35 patients. 26 patients suffered from coronary heart disease and 9 patients from dilative cardiomyopathy. The stimulation study was performed at a ventricular driving rate of 120/min with one and two premature ventricular extrastimuli. We used rectangular impulses of 1.8 ms duration at double diastolic threshold strength. RVR was scored as follows: 0: no RVR, 1: one nonstimulated RVR, 2: two nonstimulated RVR, 3: three nonstimulated RVR, 4: four to ten nonstimulated RVR, 5: more than ten nonstimulated RVR lasting less than 2 minutes, 6: sustained ventricular tachycardia or ventricular fibrillation. We found that with unipolar anodal stimulation the diastolic threshold was significantly greater and the effective refractory period of the right ventricle was significantly shorter as compared to the other stimulation techniques. Between the three different electrode configurations there were no significant differences concerning the number of consecutive ventricular depolarizations following premature stimulation. CONCLUSION: the phenomenon of RVR is not influenced by the stimulation technique (bipolar, cathodal and anodal) at double diastolic threshold.

Adult↗

PubMedDate not supplied

[Peripartum cardiomyopathy--Obstetric emergency for mother and child].

This case report describes the diagnosis, treatment as well as maternal and fetal outcome of a pregnancy complicated by peripartum cardiomyopathy (PPCM). The article demonstrates criteria that define peripartum cardiomyopathy using clinical and echocardiographic features. In absence of preexisting heart disease an acute left ventricular dysfunction of the mother led to fetal bradycardia and immediate delivery. We discuss possible causes, clinical management and long term outcome in respect of the available literature. Future pregnancies should be avoided with at least 50 % risk of recurrence.

Adult↗

PubMedDate not supplied

Clinical electrophysiological properties of N-allyl-clonidine (ST 567) in man.

The electrophysiological properties of N-allyl-clonidine (ST 567) were studied in 18 patients. Four of these patients were pretreated with intravenous propranolol, 0.2 mg/kg, and atropine, 0.04 mg/kg, to induce autonomic blockade. ST 567 produces a sustained bradycardiac effect at a dose of 40 mg, i.v., in patients without (group I) and with (group II) autonomic blockade. The mean increase in Group I was 23% and in group II, 42%. The sinus node recovery time increased in both groups, from 1,151 +/- 73 to 1,310 +/- 81 msec in group I, and from 995 +/- 145 to 1,599 +/- 248 msec (means +/- SEM) in group II. The corrected sinus node recovery time was unaffected by ST 567 in Group I and increased from 165 +/- 50 to 427 +/- 117 msec in group II. The sinoatrial conduction time was unaffected by ST 567 in group I. The effective refractory period of the right atrium, the atrioventricular node and the right ventricle, as well as the functional refractory period of the atrioventricular node, were unaffected by ST 567 in patients without autonomic blockade. Intra-atrial, atrioventricular, and intraventricular conduction were also not altered by this drug. Thus, the electrophysiological profile of ST 567 differs from other bradycardia-inducing agents such as beta-blockers or calcium antagonists.

Adult↗