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Biomedical subjects

D L Clement

Publications and source records attributed to D L Clement.

At least 145 records · Page 8Linked to original sources
PubMed1987

Effect of ketanserin in the treatment of patients with intermittent claudication: results from 13 placebo-controlled parallel group studies.

The effect of ketanserin on intermittent claudication was assessed in 13 placebo-controlled parallel group studies following basically the same protocol. After a single-blind placebo run-in period of 1-2 months, the patients randomly received either ketanserin (n = 152) or placebo (n = 158) for 3-6 months. Data on walking distance, assessed on the treadmill, were available in 12 centers (239 patients). Walking distance significantly increased in seven centers with ketanserin and in two centers with placebo. In two centers, the intergroup comparison between ketanserin and placebo was significantly in favor of ketanserin; in one center, it was in favor of placebo. A pooled analysis of all data on walking distance showed that ketanserin significantly increased walking distance by 65%, whereas placebo significantly increased it by 25%. However, the intergroup comparison does not show significant differences. Comparison of individual responses, on the other hand, showed that more patients experienced a doubling of walking distance on ketanserin than on placebo (25 versus 13%), and fewer patients deteriorated on ketanserin than on placebo (23 versus 32%); this difference in response rate is significant (p less than 0.05). In these studies there was a striking difference in drop-out rate between ketanserin and placebo. In total, 25 patients dropped out during placebo treatment versus 14 during ketanserin treatment. Nine of the 25 dropouts on placebo suffered severe "cardiovascular events," whereas no such events were observed in the ketanserin group. This difference is highly significant and suggests that ketanserin may have a vascular protective effect in patients with intermittent claudication. This possibility is being investigated in a prospective trial (PACK trial).

Blood Pressure↗
PubMed1987

Effect of calcium antagonists on ambulatory blood pressure and its variations.

Our previous studies have shown that blood pressure variability is not linked to activity of the adrenergic nervous system but that a small part of the variation is due to vagal nervous tone. The present work investigates whether myogenic activity of blood vessels could be responsible for the blood pressure variations. To test this hypothesis, variability was measured before and after administration of nifedipine, known to decrease spontaneous vascular contractions. In 17 patients with moderate essential hypertension, blood pressure was measured every 30 min for 12 h with a device recording Korotkoff's sounds on tape. Blood pressure variability was defined as the standard deviation of the mean of all readings. Placebo, nifedipine (20 mg b.i.d. in a slow-release formulation) alone and in combination with atenolol (50 mg b.i.d.), and atenolol alone were given double-blind for 3 weeks each. At the end of each period, a 12 h blood pressure profile was recorded. Systolic blood pressure significantly decreased with any of the drugs used; the combination of nifedipine and atenolol caused a greater decrease than that of any of the drugs alone. Diastolic blood pressure only decreased with the combination of nifedipine and atenolol. Nifedipine did not cause significant changes in systolic or diastolic variability; a small but nonsignificant decrease in diastolic variability was seen with atenolol and the combination of atenolol and nifedipine. The present data do not support the hypothesis that blood pressure variability is linked to myogenic vascular activity because no decrease in blood pressure variability was seen with nifedipine.

Adult↗
PubMed1987

Cardiac contusion.

During a consecutive period of 24 months, 244 patients with a major trauma were admitted to the Intensive Care Unit. From this pool of patients 60 consecutively were selected who did fulfill the selected criteria. We intended to determine within this studygroup the incidence, clinical features and outcome of patients with myocardial contusion (MC). We could conclude that no currently used diagnostic test may be seen as an accurate prediction of patients who still develop morbidity or mortality from cardiac contusion. Data from the literature suggest that at present only radionuclide angiography, direct hemodynamic measurement with construction of a Starling curve, and/or 2D-echocardiography may be useful in the identification of the patients at the greatest risk and predictive of the severity of the myocardial injury.

Adult↗
PubMed1987

Right ventricular endomyocardial biopsy: clinicopathologic correlates in 64 consecutive patients.

Endomyocardial biopsy is a safe, reliable, and reproducible technique to confirm or establish the diagnosis of the pathology that affects cardiac function in conditions previously classified as cardiomyopathies of unknown cause. The first 64 consecutive patients to undergo endomyocardial biopsy were reviewed to determine its utility in various clinical settings. Furthermore a review of literature relating to endomyocardial biopsy is presented. On the basis of these findings, we conclude that endomyocardial biopsy is indicated in the clinical setting of dilated cardiomyopathy, for evaluating underlying myocarditis. In patients with dysrhythmias or clinical myocarditis, endomyocardial biopsy may disclose myocarditis or changes consistent with congestive cardiomyopathy. In patients with systemic disease endomyocardial biopsy is instructive to prove or to exclude myocardial involvement. In patients with angina-like chest pain but with normal coronary angiograms or exercise tests, endomyocardial biopsy may prove underlying heart disease.

Biopsy↗
PubMed1986

Embolization complicating coronary angioplasty in the presence of an intracoronary thrombus.

Two cases of coronary occlusion and subsequent embolization during percutaneous coronary angioplasty (PTCA) are described. Prior to PTCA, angiographic evidence of intracoronary thrombus was present. Abrupt reclosure after dilation was treated by successful redilation. However, coronary embolization of thrombus debris occurred downstream in one patient and into an adjacent coronary branch in the second patient.

Angioplasty, Balloon↗
PubMed1986

An implantable antitachycardia pacemaker with back-up pacing and scanning burst mode.

We used an automatically triggered antitachycardia device (PASAR 4171) which is able to provide up to 7 stimuli in the atrium of three patients with AV-nodal tachycardia. A PASAR 4172 was implanted in a patient with WPW which gave two stimuli in the right ventricle. One revision was needed due to exit block. Temporary undersensing occurred in one patient. Atrial fibrillation occurred for the first time postoperatively in the WPW patient, without major side-effects. Treatment with low dosage amiodarone was initiated to prevent recurrence. At follow-up, magnet application was useful to induce supraventricular tachycardia in the three 4171 patients with 4171 devices, proving effective termination of tachycardia. Back-up pacing or concertina mode were used in 3 of 4 patients.

Adult↗
PubMed1986

Comparison between ultrasonic and thermodilution cardiac output measurements in intensive care patients.

The reliability of ultrasonic cardiac output measurement was assessed using a commercial device that combines A-mode aortic root diameter determination and continuous wave (CW) Doppler flow velocity measurement in the ascending aorta. We compared this method with thermodilution (TD) cardiac output in 41 intensive care patients. Aortic root diameter measurement with A-mode was not possible in four (10%) patients. Using strictly defined criteria based upon our initial experience, we could not obtain acceptable CW Doppler flow signals in nine (22%) patients. Thus, ultrasonic cardiac output measurement was possible in 28 (68%) patients in whom there was an excellent correlation with cardiac output (r = 0.97; p less than .001). This study demonstrates that the transcutaneous CW Doppler method for measuring cardiac output is accurate and reliable in a limited percentage of ICU patients. Combining the CW Doppler with B-mode echocardiogram increases the applicability when an A-mode measurement is not possible.

Adult↗
PubMed1986

Effect of indoramin on finger circulation in patients with Raynaud disease.

The effect of indoramin was investigated on finger circulation in 20 patients with primary Raynaud disease. After placebo run-in, indoramin (50 mg t.i.d. per os) and placebo were given double-blind and in randomized order, each for 6 (protocol 1) and 3 weeks (protocol 2). No significant changes in blood pressure and heart rate were observed. Finger blood flow, measured with venous occlusion plethysmograph, increased significantly (p less than 0.025) with indoramin as compared with placebo, and local calculated resistance decreased when measured at room temperature (protocol 1). In protocol 2 flow was measured at the end of a 6-min contact with water temperature of 40, 30, 20, 10 and 5 degrees C, respectively. It was shown that the difference between indoramin and placebo was largest at high temperatures and was clearly decreased at lower temperatures. Thus, the present data objectively document that indoramin is capable of favorably influencing skin circulation, but this effect is less pronounced at lower temperatures.

Blood Pressure↗
PubMed1986

Vasodilator effects of enalapril in patients with arterial hypertension.

Although it has been recognized that enalapril lowers blood pressure by reducing the total peripheral vascular resistance, its direct effect on blood vessels is largely unknown. Little information is available about the influence of enalapril on the different vascular regions. Ten patients with moderate essential hypertension were treated with enalapril 20 mg daily in a double-blind, placebo controlled cross-over study for six weeks during each period. Blood pressure and heart rate were measured in supine, sitting and standing position. Venous capacity was derived from pressure volume curves plotted simultaneously at forearm and calf. Arterial blood flow at rest and during reactive hyperemia was measured at calf and finger by plethysmography. Enalapril increases venous capacity in upper and lower limbs in patients with moderate essential hypertension. Also, there is vasodilation of calf and finger arteries both at rest and during reactive hyperemia. Finger and calf arteries contribute to the decrease of the total peripheral vascular resistance during treatment with enalapril; thus, ACE inhibition is capable of correcting the increased peripheral resistance which often is the main cause of arterial hypertension.

Clinical Trials as Topic↗
PubMed1986

Effect of DC-shocks of 400 Joules on the AV-node.

Ablation of the AV-node with direct current shocks and 6-French U.S.C.I. catheters was performed in 8 patients with disabling supraventricular arrhythmias. An initial shock of 400 Joules was chosen in most instances. In all patients transient or permanent complete AV-block was obtained. For one patient the procedure was considered a failure, after three sessions. Five patients remain in complete AV-block. Average escape rhythm at first ambulatory follow-up was 47 bpm. The block seems to be situated at the level of the bundle of His, or distal of this level. The other two patients are clinically improved with impaired AV-conduction. A pacemaker was implanted in all patients.

Aged↗
PubMed1985

Efficacy of an implanted automatic defibrillator which had induced atrial fibrillation.

A 54 year old man with refractory life threatening ventricular tachycardia was given an automatic defibrillator. The initial system was a transvenous defibrillator coil electrode and this was later modified by implantation of two patch electrodes at thoracotomy. The modified system successfully controlled ventricular tachycardia. On one occasion reversion of ventricular tachycardia by the defibrillator precipitated atrial fibrillation, a previously unreported side effect.

Atrial Fibrillation↗
PubMed1985

Effect of felodipine and metoprolol on muscle and skin arteries in hypertensive patients.

The antihypertensive and vasodilator effects of felodipine, a new calcium antagonist of the dihydropyridine group, were examined in 15 patients with moderate to severe hypertension. Flow was measured simultaneously at the calf and finger using a venous occlusion ECG-triggered plethysmograph. Measurements were made at rest, during handgrip and during reactive hyperaemia. Felodipine (12.5 mg, orally) was given after placebo treatment and after 3 weeks' treatment with metoprolol. It was also given for 3 weeks in combination with metoprolol. Felodipine caused a significant decrease in blood pressure which was similar in the supine, sitting and standing positions without causing any orthostatic reaction. The antihypertensive effect was accompanied by an increase in heart rate, dilatation of calf arteries and, to a lesser degree, dilatation of finger arteries. However, the degree of vasodilatation diminished with long term treatment. Metoprolol prevented the increase in heart rate but not vasodilatation. Felodipine decreased the potential for further dilatation in certain situations, as shown during reactive hyperaemia, although vasoconstrictor responses during the handgrip test remained unimpaired.

Adult↗