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Biomedical subjects

P W Westerhof

Publications and source records attributed to P W Westerhof.

At least 19 recordsLinked to original sources
PubMed1995

Clinical relevance of Doppler pulmonary venous flow characteristics in constrictive pericarditis.

The purpose of this study was to determine the diagnostic value of Doppler pulmonary venous flow in constrictive pericarditis, as assessed by transoesophageal echocardiography. It has been demonstrated previously that increased respiratory variation in Doppler pulmonary venous, but not in transmitral flow velocities, can identify patients with constrictive pericarditis, when transoesophageal echocardiography is used. In the present study we compared a group of 10 patients with constrictive pericarditis and a control group of 15 normal subjects with respect to pulmonary venous and transmitral flow velocities and their respiratory variation. Peak velocities and velocity time integrals of the systolic, early diastolic and late diastolic reversed pulmonary venous flow waves were measured. Peak velocities and velocity time integrals of the early and late diastolic transmitral flow waves were also measured. Measurements were made irrespective of the respiratory cycle, at the onset of inspiration and at the onset of expiration. Values for inspiration and expiration were expressed as percent difference of those obtained irrespective of the respiratory cycle. Peak velocity and velocity time integral of the pulmonary venous systolic and diastolic waves were significantly lower than in normal subjects. Furthermore, the difference between peak velocities of the diastolic wave obtained at the onset of inspiration and obtained irrespective of the respiratory cycle was significantly larger in constrictive pericarditis than in the control group (-20% vs -9%, P < 0.05). This also applied to the difference between velocity time integrals of the diastolic wave obtained at the onset of inspiration and obtained irrespective of the respiratory cycle (-22% vs -12%, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Use of sumatriptan (Imigran) in a female patient with coronary spasm].

Sumatriptan (Imigran), an effective drug against symptoms of migraine may cause a sensation of thoracic oppression. In some patients, this is accompanied by ECG alterations. In such cases, the underlying mechanism is probably coronary spasm, although this has never been demonstrated angiographically. The case is described of a young woman who was hospitalized after resuscitation because of ventricular fibrillation. One week previously, after subcutaneous administration of sumatriptan, she had had chest pains for half an hour. A spasm provocation test during coronary angiography gave a positive result. The patient was treated with a calcium antagonist following which she remained free of symptoms. In patients with chest pain after administration of sumatriptan, it is necessary to use this drug cautiously; spasm of the coronary arteries as a cause should be excluded.

Adult↗
PubMed1994

Transesophageal pulsed-Doppler echocardiographic evaluation of transmitral and pulmonary venous flow during ventilation with positive end-expiratory pressure.

During mechanical ventilation with high levels of positive end-expiratory pressure (PEEP) several hemodynamic changes occur, the mechanism of which has been the subject of various previous studies. The effects of increasing levels of PEEP during mechanical ventilation were measured on left atrial and left ventricular filling dynamics, as assessed by pulmonary venous and transmitral flow velocities, respectively. Using transesophageal echocardiography in 12 patients, Doppler flow velocities of pulmonary venous and transmitral flow were studied at baseline (0 cmH2O PEEP) and at 5, 10, 15, and 20 cm H2O with 10-minute intervals, and once more after removal of PEEP. In 2 of the 12 patients, PEEP could not be increased beyond 15 cmH2O, because cardiac index fell below 2.0 L/min/m2. Pulmonary venous flow velocity and velocity time integral during systole significantly decreased from 48 +/- 7 cm/s and 10.3 +/- 2.2 cm at baseline to 35 +/- 6 cm/s and 5.7 +/- 2.5 cm at 20 cmH2O PEEP, respectively (P < 0.01). In contrast, early and late diastolic velocities and velocity time integrals did not change. In regard to transmitral flow, both early and late diastolic velocities significantly decreased from 51 +/- 7 cm/s and 50 +/- 9 cm/s at baseline to 38 +/- 7 cm/s at 20 cmH2O PEEP, respectively (P < 0.01). Early and late diastolic velocity time integrals decreased from 6.1 +/- 1.8 cm and 4.7 +/- 1.0 cm to 4.5 +/- 1.0 cm (NS) and 3.4 +/- 0.7 cm (P < 0.05), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Nd:YAG laser-assisted angioplasty in femoropopliteal artery occlusions: "hot" versus "cold" recanalization with transparent contact probe.

Percutaneous recanalization of femoropopliteal artery occlusions (1-21 cm; median, 8 cm) was attempted in 50 patients. A 2.2-mm-diameter contact probe catheter connected to a continuous-wave neodymium yttrium aluminum garnet (Nd:YAG) laser was used. The laser was activated (15 W, 1-second pulses) only if too much resistance was met. Balloon angioplasty was performed after successful traversal of the occlusion. Primary success was achieved in 40 of 50 patients (80%). In 20 cases, recanalization was achieved mechanically (cold group). In the other 20 cases, recanalization was achieved with the help of laser irradiation (hot group: 15-405 J; median, 90 J). Except for the length of the obstruction (longer in the cold group), the two groups did not differ in baseline characteristics. Neither the length of the occlusion nor the duration of symptoms correlated with failure or success or with the delivered laser energy. Cold and hot groups did not differ with regard to functional improvement and angiographic patency at 3 and 12 months (94% +/- 4). Thus, brief laser activation doubled the cold primary success rate, but the major action of the laser contact probe is mechanical remodeling of the obstruction.

Adult↗
PubMed1989

[Percutaneous recanalization of occluded upper leg arteries using laser treatment].

Percutaneous transluminal laser recanalization was attempted in 21 patients with occluded superficial femoral arteries and 'life style limiting claudication'. Primary success was achieved in 20 (95%) of these total occlusions. In 7/21 no laser energy was required. At one month only 1 patient had claudication and the mean Doppler ankle/arm systolic pressure ratio had increased by 0.36 +/- 0.19 (p less than 0.001) at rest and 0.47 +/- 0.34 (p less than 0.001) after exercise. Complications directly attributable to the procedure were: perforation (1), peripheral embolic episodes (2), haematoma (1), transient vasospasm (2). All complications could be treated non-surgically. These preliminary data suggest that laser recanalization of relatively short occlusions of the superficial femoral artery, followed by balloon dilatation, may be accomplished with satisfactory acute and short-term results, but not without risk.

Aged↗
PubMed1989

Electrode catheter ablation for ventricular tachycardia: efficacy of a single cathodal shock.

Electrode catheter ablation was used to treat 11 distinct types of sustained ventricular tachycardias in eight patients. Rigid electrophysiological criteria were used to identify five left and five right ventricular arrhythmogenic sites; one of them gave rise to tachycardia with two distinct configurations. A single R-wave-synchronised 250 or 150 J cathodal shock was delivered at each site. One patient had mildly symptomatic episodes of sustained ventricular tachycardia during the first four days after the shock--there were no other complications. At discharge none of the patients was taking antiarrhythmic drugs. They were followed for 8-20 months (mean 14). Ablation abolished five of the 11 ventricular tachycardias. There was no recurrence in three of the eight patients. In two patients identical ventricular tachycardias recurred because the identification of the arrhythmogenic site was incorrect.

Adult↗
PubMed1985

Is there an indication for coronary angiography in patients under 60 years of age with no or minimal angina pectoris after a first myocardial infarction?

Coronary angiography and exercise stress tests were performed in 91 consecutive patients under 60 years of age having either no or only mild angina pectoris with or without medication after a first myocardial infarction. Nine (10%) patients had angiographic high risk coronary artery disease defined as three vessel disease, left main stenosis, or proximal stenosis of the left anterior descending artery. Eighteen patients had a positive electrocardiographic exercise stress test including eight of the nine patients with angiographic high risk coronary artery disease. It may be concluded therefore that coronary angiography to detect high risk coronary artery disease in this group can be restricted to patients with a positive exercise stress test. This policy would obviate the need for about 80% of coronary angiograms performed in this age group.

Adult↗
PubMed1977

Removal of a fragment of catheter entrapped in a Bjork-Shiley aortic valvular prosthesis. Transarterial approach using a modified loop-snare technique.

Fracture of a left atrial catheter made of polyethylene and its subsequent embolization and entrapment in a Bjork-Shiley aortic valvular prosthesis is reported in a 62-year-old woman. The entrapped fragment of the catheter was retrieved by a transarterial approach using a homemade modified snare-loop device. Measures to prevent such a complication should be directed towards avoidance of force when removing such catheters. In addition, their length should be determined prior to insertion and again after removal, in order to detect their possible fracture and loss at once.

Aortic Valve↗