Manfred Mauser

Initial angiographic results in ablation of atherosclerotic plaque by percutaneous coronary excimer laser angioplasty without subsequent balloon dilatation.

Percutaneous transluminal coronary excimer laser angioplasty was performed in 15 patients using a 1.3-mm diameter laser catheter. The catheter consists of 20 concentric quartz fibers of 100 microns diameter each located around a central lumen suitable for a 0.014-inch flexible guidewire. The catheter was coupled to an excimer laser delivering energy at a wavelength of 308 nm and at a pulsewidth of 60 ns. Quantitative analysis of the angiograms documented a decrease from 77 +/- 15% diameter stenosis before intervention to 40 +/- 22% after the first irradiation cycle and to 21 +/- 17% after termination of laser ablation. The minimal lumen diameter increased from 0.4 +/- 0.2 to 1.3 +/- 0.4 and to 1.6 +/- 0.4 mm, respectively. Vessel reocclusion was seen in 2 patients at 24-hour control angiography. No procedure-related major complications such as vessel perforation occurred. In 8 patients, however, intraluminal lucencies were seen, which were persistently visualized 24 hours after intervention in 6 patients. Despite pretreatment with intracoronary nitroglycerin, coronary spasm occurred in 8 patients and was reversible after additional sublingual vasodilator therapy. The results of this pilot study suggest that percutaneous coronary excimer laser angioplasty is feasible and effective for ablation of coronary lesions in selected patients and can be performed without subsequent conventional balloon angioplasty. The clinical impact of this new interventional technique, however, remains to be assessed.

Myocardial properties of the new dihydropyridine calcium antagonist isradipine compared to nifedipine with or without additional beta blockade in coronary artery disease

Isradipine is a new dihydropyridine calcium antagonist with myocardial effects significantly different from those of nifedipine, as shown by in vitro and animal experimental data. Isradipine selectively inhibits the sinus node but not the atrioventricular conduction and its negative inotropic action is much less if administered in a dose of comparable peripheral effects. To study these effects in man, 40 patients with coronary artery disease were divided into 2 groups receiving either a continuous 30-minute intravenous infusion of 2 mg of nifedipine or 0.5 mg of isradipine, doses that resulted in a comparable afterload reduction (decrease of systemic vascular resistance: nifedipine -22.1%, isradipine -25%, p less than 0.001). Ten patients in each group received an additional intravenous bolus of 5 mg of propranolol at the end of the calcium antagonist administration to antagonize its induced adrenergic reflex mechanisms. The heart rate significantly increased after nifedipine only (+9.2%, p less than 0.001), experienced no change after isradipine and the nifedipine and propranolol combination and decreased after the combination of isradipine and propranolol (-9.6%, p less than 0.001). This resulted in a significant decrease of the rate pressure product with isradipine (-12.5%, p less than 0.001) but not with nifedipine. As a result of the afterload-induced adrenergic reflex mechanisms, the maximal derivative of the left ventricular pressure increased after isradipine administration (+13.5%, p less than 0.001) and was unchanged after nifedipine, which demonstrates the significantly less negative inotropic properties of isradipine as compared with nifedipine.

Effect of right coronary artery occlusion during percutaneous transluminal coronary angioplasty on right ventricular performance

Abstract The effects of acute ischemia on left ventricular volumes and function have been studied extensively in animal models and, more recently, in patients with coronary artery disease during percutaneous transluminal coronary angioplasty (PTCA) of the left coronary artery.ls2 Less attention, however, has been focused on the performance of the right ventricle in patients with chronic coronary artery disease or during acute occlusion of the right coronary artery (RCA). In patients with coronary artery disease, ischemia induced by balloon inflation during PTCA is a setting comparable to short-term coronary artery occlusion in the animal laboratory, and provides the opportunity to study the effects of acute ischemia on ventricular function in humans. We describe the effects of acute ischemia on right ventricular (RV) performance in patients undergoing PTCA of the RCA.

Intraoperative valvuloplasty in calcific aortic stenosis: a study comparing the mechanism of a novel expandable device with conventional balloon dilatation.

In selected patients with calcific aortic stenosis, balloon valvuloplasty is an intermediate alternative to surgery. The effect of balloon valvuloplasty to increase valve area, however, is limited and the restenosis rate is high during follow-up. To improve the results and reduce the complication rate, a new device for valvuloplasty of calcific aortic stenosis was developed. This system consists of three expandable prongs mounted on a freely movable catheter tip. To evaluate the efficacy of this new device, valvuloplasty was performed in 10 patients with severe aortic stenosis intraoperatively just prior to valve replacement. Comparison was made with the results of conventional balloon dilatation performed in an additional 20 patients during surgery. Using the new device, the relative orifice area increased from 10 +/- 3% before to 20 +/- 6% following intervention. However, in only one patient was a considerable increase of static valve area (greater than 15%) found. The results were comparable to the effect of conventional balloon dilatation, which led to an increase of orifice area from 12 +/- 7% to 24 +/- 10%. With both systems, the best results were achieved in patients with aortic stenosis and significant commissural fusion. In contrast, in bicuspid or tricuspid valves without fused commissures the effect of the intervention was limited. Because complete obstruction of the aortic valve does not occur during dilatation, this new device might be superior to conventional balloon dilatation. Preselection of patients according to the morphology of the valve seems mandatory to improve the success and reduce the complication rate of valvuloplasty in aortic stenosis.

Acute hemodynamic effects of adibendan, a new phosphodiesterase inhibitor, for severe congestive heart failure

Abstract Phosphodiesterase inhibitors show promise in the treatment of patients with severe congestive heart failure (CHF). 1,2 Adibendan is a new, orally active benzimidazole derivative, which exhibits phosphodiesterase inhibition and sensitivation of the myofilaments to calcium. 3

Value of a modified continuity equation method to quantify mitral valve area in patients with mitral stenosis and sinus rhythm

SummaryTo quantify valve area in mitral stenosis, a modified continuity equation method using continuous wave Doppler and thermodilution measurements was applied. In 14 patients with mitral stenosis and sinus rhythm (age: 49±11 years), transmitral flow velocity was recorded by continuous wave Doppler during right and left heart catheterization. Mitral valve area was calculated by three different methods: 1. According to the continuity equation, stroke volume (thermodilution technique) was divided by the registered time velocity integral of the mitral stenotic jet (continuous wave Doppler). 2. Mitral valve area was calculated by the pressure half-time method. 3. Simultaneous pulmonary capillary wedge and left ventricular pressure measurements were used for determination of mitral valve area according to the Gorlin formula. The mitral valve area determined by application of the continuity equation (y) showed a close correlation to the valve area calculated by the Gorlin equation (x):y=0.73x+0.12, SEE=0.11 cm2,r=0.88,P<0.001. In contrast, the correlation between mitral valve area determined by pressure half-time (y) and the Gorlin formula (x) was not as good:y=0.77x+0.11, SEE=0.26 cm2,r=0.65,P<0.05. Thus, the continuity equation method using combined continuous wave Doppler and thermodilution technique allows a valid determination of mitral valve area. In patients with mitral stenosis and sinus rhythm, this technique is superior to the noninvasive determination of mitral valve area by the conventional pressure half-time method.

Kurz- und Langzeiteffekte der invasiven Therapie (PTCA, ACVB-OP) bei Patienten mit instabiler Angina pectoris

Die perkutane transluminale koronare Angioplastie (PTCA) wurde im Verlauf der letzten zehn Jahre zu einem festen Bestandteil der Therapie der koronaren Herzkrankheit [2, 5, 6, 11, 12].

Interobserververgleich der quantitativen lokalen Wandfunktionsanalyse des linken Ventrikels bei der Belastungscineventrikulographie

SummaryDuring diagnostic heart catheterization biplane cineventriculograms of 46 patients at rest and directly after bicycle ergometry (72.8±27.8 W) were performed. The aim of the study was to determine the value of local wall motion analysis under physical exercise. Therefore two observers independently analyzed global and local left ventricular parameters.38 patients had coronary artery disease, 23 with a history of myocardial infarction. Enddiastolic (EDV) and endsystolic volume (ESV) were evaluated and ejection fraction (EF) was calculated. Local wall motion was analyzed using a radial model with 60 radii in the 30° RAO- and 60° LAO-Projektion. A systolic segmental shortening was determined for the anterobasal (AB), anterolateral (AL), apical (AP), diaphragmatic (DP), posterobasal (PB) (30°-RAO), septal (SE) and posterolateral (PL) area (60°-LAO).Global functional parameters (EDV, ESV, EF) revealed good correlations between both observers with correlation coefficients (r) varying from 0.83 to 0.92. Local wall motion had sufficient correlations (r) at rest and during exercise (data in brackets) in the RAO-projektion: AB: 0.88 (0.73), AL: 0.69 (0.72), AP: 0.82 (0.78), DP: 0.77 (0.75), PB: 0.78 (0.78) and in the septal segment (LAO-projection): 0.69 (0.71). Less sufficient correlations were found in the posterolateral segment (LAO, especially at rest: 0.50 (0.69).Thus, global ventricular parameters can be determined at rest and during exercise independently of the observer. Local wall motion, too, can be quantified with sufficient accuracy with exception of the posterolateral area in the LAO-projektion.During diagnostic heart catheterization biplane cineventriculograms of 46 patients at rest and directly after bicycle ergometry (72.8 +/- 27.8 W) were performed. The aim of the study was to determine the value of local wall motion analysis under physical exercise. Therefore two observers independently analyzed global and local left ventricular parameters. 38 patients had coronary artery disease, 23 with a history of myocardial infarction. Enddiastolic (EDV) and endsystolic volume (ESV) were evaluated and ejection fraction (EF) was calculated. Local wall motion was analyzed using a radial model with 60 radii in the 30 degrees RAO- and 60 degrees LAO-Projektion. A systolic segmental shortening was determined for the anterobasal (AB), anterolateral (AL), apical (AP), diaphragmatic (DP), posterobasal (PB) (30 degrees-RAO), septal (SE) and posterolateral (PL) area (60 degrees-LAO). Global functional parameters (EDV, ESV, EF) revealed good correlations between both observers with correlation coefficients (r) varying from 0.83 to 0.92. Local wall motion had sufficient correlations (r) at rest and during exercise (data in brackets) in the RAO-projektion: AB: 0.88 (0.73), AL: 0.69 (0.72), AP: 0.82 (0.78), DP: 0.77 (0.75), PB: 0.78 (0.78) and in the septal segment (LAO-projection): 0.69 (0.71). Less sufficient correlations were found in the posterolateral segment (LAO, especially at rest: 0.50 (0.69). Thus, global ventricular parameters can be determined at rest and during exercise independently of the observer. Local wall motion, too, can be quantified with sufficient accuracy with exception of the posterolateral area in the LAO-projektion.