Biomedical subjects

D Dobreanu

Publications and source records attributed to D Dobreanu.

6 recordsLinked to original sources

PubMed2004

Study of the efficiency of the head-up tilt test with nitroglycerin challenge in the diagnosis of vasovagal syncope.

UNLABELLED: Syncope is defined as a transient, self-limited loss of consciousness. It is an important cause of morbidity in general population and the vasovagal syncope (VVS) is a common clinical problem which often leads to hospital admission, multiple office visits, and performing of many diagnostic tests. Head-up tilt table testing (HUTT) is a widely used diagnostic tool, with proved efficiency in diagnosing the many types of VVS. The aim of our study was to assess the efficacy of the HUTT with sublingual nitroglycerin (NTG) challenge for the diagnosis of vasovagal syncope. PATIENTS AND METHODS: The study groups consisted of 72 patients (37 women, 35 men), mean age (+/-SD) 38.5 +/- 15.7 years, referred to our clinic for syncope of unknown origin and 16 healthy volunteers as control subjects (9 women and 7 men) with a mean age 26 +/- 6.5 years and no history of syncope. The HUTT protocol was performed in the morning after an overnight fast, with a 15 minutes supine equilibration phase followed by a 30 minutes drug free tilt phase at an angle of 70 degrees. If no positive response was recorded, 400 micrograms of NTG spray were given sublingually and the HUTT continued for 20 minutes. RESULTS: The HUTT was positive in 58 patients (80.5%) and negative in 14 (19.5%) while in the control subjects 4 (25%) had positive HUTT response. The sensitivity of the HUTT protocol with nitroglycerin challenge used in our study was 81% and the specificity was 75% (p<0.0001). CONCLUSION: The described HUTT protocol appears to be a simple and efficient tool for the diagnosis of syncope associated with normal ECG and no signs of organic heart disease. The sublingual nitroglycerin challenge was safe to use and showed no side effects while keeping the sensitivity and specificity of the test to an accepted level.

Administration, Sublingual↗

PubMedDate not supplied

Treatment of atrial flutter and rapid atrial tachycardia with endocavitary atrial pacing.

Fourteen patients with atrial flutter (AFL) and rapid atrial tachycardia (AT) (8 AFL type I, 2 AFL type II and 4 AT) were treated with endocavitary atrial pacing (EAP). In 10 patients no antiarrhythmic agent was during this study and in 4 patients digoxin and/or verapamil was administered before. Conversion to sinus rhythm was successfully achieved in 7 patients, 50% (4 AFL type I and 3 AT). Primary success rate (return to sinus rhythm either immediately or after < 10 min of atrial fibrillation) was 71% (5/7) (2 AFL type I and 3 AT); delayed success (conversion to sinus rhythm in > 10 min, but < 24 h) was observed in 2 cases (29%) with AFL type I. At five patients AFL was converted in stable atrial fibrillation (4 AFL type I and 1 AFL type II). EAP failed to terminate the arrhythmia in 1 patient with uncommon AFL (type II) and 1 case with AT. EAP included single extrastimuli, coaction, single decremental atrial extrastimuli and incremental atrial pacing (burst) during AFL or AT. In conclusion, EAP is a method with few complications and has efficacy for converting AFL and rapid AT sinus rhythm or to atrial fibrillation.

Adult↗

PubMedDate not supplied

The monophasic action potential: a simple in vivo model to evaluate the effects of antiarrhythmic drugs at atrial level.

Monophasic action potential (MAP) represents an extracellular recording of electrical potentials variations produced simultaneously by several cells. Even if it does not represent the real cellular action potential, monophasic action potential generally reproduces with accuracy that aspect, being useful especially in the assessment of myocardial repolarisation phases. Monophasic action potential recording was performed with a quadripolar catheter designed by Franz; the quality of recordings was good and the procedure is safe. In clinical electrophysiology, monophasic action potential may be helpful in the study of certain aspects that cannot be evaluated adequately by standard electrophysiological techniques. The study was performed on six patients, in drug-free state. The duration of monophasic action potential at 90% of repolarisation and the atrial effective refractory period, at three basic cycle lengths (600, 500 and 400 msec) were determined. Both monophasic action potential duration at 90% of repolarisation and the atrial effective refractory period shortening at short cycle length and a linear correlation between these two parameters were seen. We conclude that the correlation between monophasic action potential duration and the effective atrial refractory period may be a simple and useful model to characterise in vivo the electrophysiologic profile of antiarrhythmic drugs.

Action Potentials↗

PubMedDate not supplied

Hypothesis of transition in two ways from atrial fibrillation to sinus rhythm.

A hypothesis of transition from atrial fibrillation to sinus rhythm in close relation with monophasic action potential duration is proposed. The first way: the prolongation of the right atrial refractoriness reduces the wave fronts below a critical number and their collision terminates the arrhythmia. The second way: progressive shortening of refractoriness at a critical level with block and collision of wave fronts.

Atrial Fibrillation↗

PubMedDate not supplied

Postextrasystolic changes in ventricular depolarization (electrocardiographic observations).

Postextrasystolic changes in ventricular depolarization were found in patients with coronary artery disease in two situations: a) after a compensatory postextrasystolic pause and, b) after an interpolated ventricular beat. The explanation and the underlying conditions of this phenomenon are discussed. In our opinion the postextrasystolic change may be a silent myocardial ischemia.

Cardiac Complexes, Premature↗

PubMedDate not supplied

Electrophysiologic evaluation of extrinsic and intrinsic sinus node dysfunction.

Electrophysiologic investigation was done for ten patients with clinical and ECG criteria for sick sinus syndrome (SSS). Sinus node function was assessed through corrected sinus node recovery time (CSNRT) and sinoatrial conduction time (SACT), before and after autonomic blockade (AB) with propranolol 0.2 mg/kg and atropine 0.04 mg/kg, given intravenously. Four patients having electrophysiologic parameter in normal range before AB were not considered as SSS. In three patients extrinsic sinus node dysfunction (SND) was found, the pathologic values of CSNRT and SACT being normal after AB, and in one patient with sinus bradycardia, the sinus node function was difficult to be appreciated. In two patients only intrinsic SND was found and, in consequence, pacemaker device was implanted.

Adult↗