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Biomedical subjects

W Rutishauser

Publications and source records attributed to W Rutishauser.

At least 109 records · Page 6Linked to original sources
PubMed1985

[Multivessel percutaneous coronary angioplasty].

Between August 1983 and October 1984, 44 patients (39 male and 5 female, mean age 53 years) underwent multivessel percutaneous transluminal coronary angioplasty involving 2 vessels in 37 (84%), 3 vessels in 4 (9%), 4 vessels in 1 (2%) and coronary artery bypass graft plus 1 or 2 vessels in 2 (5%). A mean of 2.2 vessels per patient were attempted. Dilatations of multiple stenoses in the same vessel were not included. Primary success was achieved in 87 of 97 vessels (90%) and in 37 of 44 (84%) patients. Primary success per patient was defined as primary success in all or at least in the strategic lesions associated with clinical improvement of the patient. Complications included one death (2%), emergency coronary artery bypass surgery in one (2%) and myocardial infarction in 2 (4%) patients. Five other patients underwent elective coronary artery bypass surgery. Recurrence of lesion was 14% (5/37 patients) during a follow-up period of 3 to 12 months. Repeat angioplasty was successful in 4 patients (80%) and unsuccessful in 1 patient who underwent elective surgery. It is concluded that, in selected cases, multivessel percutaneous transluminal coronary angioplasty is a feasible alternative to coronary artery bypass surgery, with comparable risks. A satisfactory long-term amelioration without coronary artery surgery can be obtained in 2/3 of patients.

Adult↗
PubMed1985

[Intracoronary electrocardiography during transluminal coronary angioplasty].

To continuously record an intracoronary ECG during the crucial phase of percutaneous transluminal coronary angioplasty, the coronary guide wire was connected to an ECG recorder. In 25 patients the intracoronary ECG was recorded simultaneously with standard leads I, II and III during balloon occlusion of a coronary artery for 30-60 sec. The wire serving as electrode was positioned in the distal third of the coronary artery to be dilated, thus reflecting changes in the pertinent area of the myocardium. This was the left anterior descending coronary artery in 19 patients, the left circumflex coronary artery in 4 patients, and the right coronary artery in 2 patients. Electrocardiographic signs of ischemia were observed in 16 patients (62%). They were present in both the intracoronary ECG and at least 1 of the standard leads I, II or III in 11 patients, in the intracoronary ECG exclusively in 4 patients, and in the standard lead I exclusively in 1 patient. Sensitivity and specificity as an indicator for chest pain during balloon occlusion were 88% and 89% respectively for the intracoronary ECG and 63% and 78% respectively for the standard leads I, II and III. Sensitivity and specificity as an indicator for poor collateralization (coronary wedge pressure less than or equal to 25 mm Hg) were 100% and 69% respectively for the intracoronary ECG, and 60% and 62% respectively for the standard leads, I, II and III.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Non-selective intra-arterial digital subtraction angiography for the assessment of coronary artery bypass grafts.

Non-selective intra-arterial digital subtraction angiography (DSA) was performed immediately before selective coronary and bypass angiography in 33 consecutive symptomatic patients 48 +/- 30 months after coronary surgery, for the assessment of 75 coronary bypass grafts. Forty ml of non-ionic, low-iodine content contrast medium (iohexol) were injected into the ascending aorta at 10-20 ml/sec through a 7 or 8 F femoral pigtail catheter. Electrocardiogram-triggered images were acquired on a Siemens Digitron II apparatus in multiple projections in 24 patients and in a single projection in 9 patients. The results of this technique were compared by two independent angiographers with those of selective graft angiography in the same patients. Patency was shown by DSA in 45 of 54 grafts confirmed to be open by selective angiography (sensitivity 83%). Of 21 occluded grafts, stumps were clearly visible at selective angiography in 18 and at DSA in 9 (sensitivity for graft stumps = 50%, p less than 0.01). Of 54 patent grafts with selective angiography, the distal anastomosis could be visualized by DSA in 28 (52%), but the resolution was comparable to selective angiography in 20 grafts (37%) only. A non-significant difference in the sensitivity of DSA was observed between patent saphenous grafts to the left anterior descending coronary artery versus all other coronary arteries (95 vs 85%, respectively), while only 1 of 5 patent left internal mammary artery grafts to the left anterior descending coronary artery was visualized. In 16 of 50 grafts (32%) visualized in a second projection substantial additional diagnostic information was obtained. In conclusion, non-selective intra-arterial electrocardiogram-triggered DSA can visualize patent saphenous grafts with a high sensitivity and may be a useful screening tool for bypass grafts patency; false negatives, however, and poor visualization of distal anastomoses limit its routine clinical use.

Adult↗
PubMed1985

Recent developments of cardiac digital radiography.

Digitization in cardiovascular radiology is on the verge of its realization. Since its introduction digital subtraction angiography (DSA) is gradually replacing conventional angiography in several areas of the body. The initial tendency to avoid the arterial catheterization by intravenous injection is somewhat reversed in favor of smaller intraarterial amounts of contrast medium injected through smaller catheters at reduced rates. However, left ventriculography by intravenous route has gained widespread acceptance at rest and with exercise: motion artifacts are less crucial for ventriculography than for small arteries, in which the same motion artifacts cause a more important relative deterioration of the image, so that it has to be corrected by pixel shift. DSA is only the first step towards functional imaging, where time and other parameters are condensed in one single color coded picture. Biharmonic Fourier analysis for quantitative analysis of regional left ventricular contraction and relaxation and digital coronary radiography for evaluation of contrast progression in the coronary circulation are two areas of cardiology where parametric imaging can help to detect functional abnormalities, especially in coronary heart disease.

Arteries↗
PubMed1985

Transluminal coronary angioplasty--state of the art 1984.

Since its introduction in 1977 by Grüntzig, percutaneous transluminal coronary angioplasty (PTCA) has been increasingly applied to the treatment of coronary artery disease manifested by symptomatic ischemia. Initially only recommended for proximal short stenoses of one major coronary artery, the indication for PTCA has gradually been enlarged. Today even distally situated coronary stenoses in more than one vessel can be dilated successfully by using a steerable system. In experienced hands, an immediate improvement can be achieved in about 90% of the patients. In the realm of cost and morbidity PTCA offers obvious advantages over bypass surgery. However, indications for PTCA are more restricted than those for bypass surgery, specially in multi-vessel disease where the application of PTCA is still controversial. Moreover, long-term results are less favourable after PTCA since 25-30% of the patients show a recurrence within 6 to 12 months. Although PTCA will not replace coronary bypass surgery, it is already established as an alternative and complementary method for coronary revascularization.

Angioplasty, Balloon↗
PubMed1985

Coronary pacing during percutaneous transluminal coronary angioplasty.

To avoid venous puncture, a new concept for standby cardiac pacing during percutaneous transluminal coronary angioplasty (PTCA) and diagnostic cardiac catheterization was developed. It uses an arterial guidewire as a unipolar pacing electrode with the second electrode attached to the skin. The system was tested in 25 coronary arteries of 22 patients undergoing PTCA and in the left ventricles of 10 patients undergoing diagnostic cardiac catheterization. Coronary pacing via the guidewire used for directing the balloon catheter was possible in all patients and in 24 of the 25 coronary arteries attempted. Maximum duration of pacing was 8 min. Threshold currents ranged from 1 to 15 mA (mean 5.7). Left ventricular pacing via the same wires or standard wires used for introduction of diagnostic or guiding catheters was possible in all patients and was maintained for up to 10 min. Threshold currents ranged from 1 to 7 mA (mean 3.9). Neither method for pacing produced adverse effects during these short applications. The setup for coronary pacing also allowed recording of an intracoronary electrocardiogram during PTCA. The presented system provides backup for the rare event of sustained bradycardia during PTCA or diagnostic cardiac catheterization. If applied cautiously, it may safely and reliably replace the standby of a conventional transvenous pacing catheter.

Adult↗
PubMed1985

[Emergency cardiac pacing via a coronary vessel during percutaneous coronary angioplasty].

Percutaneous coronary angioplasty (PCA) is sometimes complicated by bradyarrhythmias necessitating emergency temporary cardiac pacing. This is usually performed by the classical transvenous endocardial approach. This experimental study investigated the possibility of using the metallic guide wire used during PCA as a monopolar electrode. Systematic electrical stimulation at different levels of the coronary arteries in 6 anaesthetised pigs showed threshold levels in the distal segments of 3 to 15 mA, close to the values observed in the right ventricule. Short periods of pacing were well tolerated. On the other hand, prolonged pacing (2 to 5 days) invariably led to the formation of a thrombus in the coronary segment occupied by the metallic guide wire and so should be avoided. This study shows that the metallic guide wire can be used as an emergency pacing electrode during PCA but this should be limited to a short period. This technique could replace the systematic introduction of classical transvenous pacing catheters.

Angioplasty, Balloon↗
PubMed1985

[Volume and regional contraction of the left ventricle studied with venous injection in subtraction angiography].

UNLABELLED: The end-diastolic and end-systolic volumes, the left ventricular ejection fraction, and segmental contraction of the left ventricle (5 areas) were determined at rest in 31 patients using two methods: conventional cineventriculography (as reference) and digital subtraction angiography by venous injection (the inferior vena cava). RESULTS: the volumes and ejection fraction obtained by digital subtraction angiography were reliable, though slightly less accurate than conventional ventriculography. Quantification of segmental contraction was satisfactory in the apical, anterolateral, and anteroinferior portions. It was less satisfactory in the posteroinferior portion with questionable reliability in the diaphragmatic portion. Qualitative dynamic assessment of contraction was satisfactory in most patients.

Angiography↗
PubMed1983

A review of the long-term effects of prazosin and hydralazine in chronic congestive heart failure.

In the last two years, six studies using prazosin in doses of 3-32 mg/day for two and 16 months have shown a persistent but variable benefit in 50-80% of those who initially responded favorably. However, serious side-effects occurred in up to 40% and, in many cases, tolerance developed. Mortality was 25-38% in 3-6 months, 50% by one year. In five studies using hydralazine (sometimes combined with long acting nitrates), 150 patients observed from six up to 29 months showed sustained benefit in 26 to 59%, while in many cases hemodynamic values returned to pretreatment values. Again side-effects were considerable, with worsening of angina, fluid retention, gastrointestinal symptomatology and, rarely, lupus erythematodes. Mortality was 28-41% in 10-12 months, higher in non-responders than in responders. Although exercise capacity increased in responders, no data are available today to prove that these vasodilators allow heart failure patients to live longer. Prudence is indicated in patients with congestive heart failure due to coronary artery disease. Furthermore, tolerance development, which only may be surmountable if discontinuation for a few weeks or switching to another drug is possible, is a serious problem limiting chronic vasodilator application.

Chronic Disease↗
PubMed1983

Different hemodynamic actions of trinitroglycerin and isosorbide dinitrate in patients with acute myocardial infarction.

The hemodynamic effects of intravenously administered trinitroglycerin (TNT) and isosorbide dinitrate (ISDN) in stechiometric equivalent doses were studied in 30 patients with acute myocardial infarction. Both drugs were given over 30 min in every patient, and the stability of the condition of the patient was checked by administering the initial drug again. Measurements were made by right heart catheterization using a balloon tip thermodilution catheter and a catheter in the radial artery. TNT and ISDN have different hemodynamic effects. By multivariate analysis it could be shown that TNT is a venous dilator, lowering mainly pulmonary capillary pressure, while ISDN acts more as a mixed vasodilator, diminishing mainly peripheral vascular resistance and increasing cardiac output. These drugs have, therefore, a different spectrum of indications in patients with acute myocardial infarction.

Cardiac Output↗
PubMed1982

[Hemodynamic effects of intravenous isosorbide dinitrate in acute myocardial infarct].

The hemodynamic effects of intravenous isosorbiddinitrate (ISDN) were studied in 15 patients with acute myocardial infarction. Pressure and flow parameters were measured by right heart and radial catheterization and by the thermodilution method. 3-9 mg/hour ISDN was infused intravenously and the hemodynamic values were measured during half an hour in clinically stable state. The statistical analysis was carried out by paired Student's t-test and factors analysis. After ISDN therapy 10 patients showed a significant fall in pulmonary capillary pressure (-24%), 9 a rise in stroke volume index (+21%) and cardiac index (+13%). Two patients only exhibited a rise in pulmonary capillary pressure (+10%) and one a fall in cardiac index (-5%). ISDN changes in pulmonary capillary pressure, stroke volume and cardiac output were mainly due to changes in pulmonary and systemic vascular resistances and much less to those in the systemic venous bed. It can be supposed that intravenous ISDN behaves more like a mixed than a venous vasodilator and can be recommended for acute myocardial infarction patients with high pulmonary capillary pressure and low cardiac output.

Adult↗
PubMed1982

Mitral valve replacement in children. Comparative study of pre- and postoperative haemodynamics and left ventricular function.

Haemodynamic variables and left ventricular function were studied before and after mitral valve replacement in 44 children age 3 to 17 years (mean 11.9 years). Thirty-nine Starr-Edwards prostheses and five Hancock prostheses were used; postoperative study took place two to six months (mean 3.9 months) after operation. Pulmonary hypertension was present preoperatively in most patients, with mean pulmonary artery pressures of 18 to 75 (mean 46.5 mmHg). Postoperatively there was a pronounced drop in pressure to a mean value of 25.6 mmHg, partially explained by a decrease in pulmonary capillary wedge pressure. Pulmonary arteriolar resistance, however, also decreased conspicuously from an average of 590 dynes s cm-5 m-2 preoperatively to 282 dynes s cm-5 m-2 postoperatively. A return to normal resistance was seen in every case when preoperative resistance did not exceed 650 dynes s cm-5 m-2; above this threshold some degree of pulmonary hypertension often persisted. The residual gradient across the prosthetic valve was slightly higher for the Hancock than for the Starr-Edwards prosthesis (mean 8.7 mmHg, vs mean 6.9 mmHg). The left ventricular end-diastolic volume was much increased before surgery, with a mean value of 190 ml/m2; it decreased conspicuously after operation to 103 ml/m2. The left ventricular ejection fraction ranged from 40% to 76% (mean 57%) before operation; there was no significant change after operation, with values ranging from 40% to 73%. This left ventricular dysfunction is probably the result of myocardial injury caused by a chronic volume overload and the sequelae of rheumatic carditis.

Adolescent↗
PubMed1982

Acute hemodynamic effects of intravenous tiapamil in patients with coronary artery disease.

The acute hemodynamic effects of intravenous tiapamil were studied during heart catheterization in 19 patients with coronary artery disease (age range 41-66 years, mean 52.4 years). 10 subjects received an initial intravenous loading dose of 1 mg/kg followed by intravenous infusion of 50 micrograms/kg/min for 15 min. The other 9 patients received an initial intravenous dose of 1.5 mg/kg which was followed by an intravenous infusion of 75 micrograms/kg/min for 15 min. Tiapamil had little effect on heart rate, intracardiac pressures and left ventricular dp/dtmax. The ejection fraction increased, but not significantly. The most striking findings were an increase in cardiac output and a decrease in systemic vascular resistance. The overall results are consistent with the drug's propensity to produce peripheral vasodilatation which outweighs its intrinsic negative inotropic property due to calcium antagonism in myocardial tissues.

Adult↗
PubMed1982

[Spontaneous cardiac rhythm in patients wearing cardiac stimulators].

Cutaneous electrical stimulation allows inhibition of permanent on-demand cardiac pacemakers. The evolution of the spontaneous cardiac rhythm was studied, using this technique of inhibition in 164 patients paced for 4 to 16 years. At implantation, 117 patients (70 p. 100) had atrioventricular block, 45 patients (27 p. 100) had sinoatrial dysfunction and 2 patients had a carotid sinus syndrome. Of these 164 patients, 153 were symptomatic. Three groups were distinguished: - 41 patients (25 p. 100) with a spontaneous ventricular rhythm at each check-up; - 75 patients (46 p. 100) with an underlying ventricular rhythm recorded when the pacemaker was inhibited by cutaneous electrical stimulation; - 48 patients (29 p. 100) with no underlying ventricular rhythm during 3 successive inhibitions of their pacemakers of 3 to 4 seconds duration on each occasion. All these patients had atrioventricular block at implantation; none had sinoatrial disease. In conclusion, disease of the atrioventricular conduction pathway, contrary to sinoatrial disease, leads to a prolonged absence of the spontaneous ventricular activity. This seems to be related to a longer survival of patients without associated pathology, and also suggests a degenerative cause of the atrioventricular block.

Adult↗
PubMed1981

Diastolic amplitude time index: a new apexcardiographic index of left ventricular diastolic function in human beings.

Left ventricular apexcardiography was performed in 260 normal subjects and 37 patients undergoing diagnostic cardiac catheterization: 13 without left heart disease (group 1), 18 with congestive cardiomyopathy (group 2) and 6 with idiopathic hypertrophic subaortic stenosis (group 3). In the patients undergoing catheterization the apexcardiogram was recorded simultaneously with left ventricular pressure (tipmanometer) and its first derivative (dP/dt). The following variables were measured in the apex tracing: (1) the time from the onset of the aortic component of the second heart sound (A2) in the phonocardiogram to the nadir of the apexcardiogram, termed total apexcardiographic relaxation time (TART), (2) the time from A2 to the onset of the systolic upstroke (C point) of the apexcardiogram (A2-C), and (3) the ratio of the A wave (A) to the total diastolic amplitude (D) of the apexcardiogram (A/D). The diastolic amplitude time index (DATI) was calculated according to the following formula DATI = (square root A2-C/TART)/(A/D). In the normal subjects the diastolic amplitude time index was 0.82 +/- 0.26 (mean +/- standard deviation). In group 1 this index was within normal limits; in groups 2 and 3 it was decreased (0.23 +/- 0.07 and 0.18 +/- 0.05, respectively). This index showed excellent correlation with specific compliance of the left ventricle (r = +0.90) and close correlations with the maximal rate of decrease of left ventricular pressure (minimal dP/dt) (r = +0.79) as well as the velocity of lengthening of the contractile elements at minimal dP/dt (r = +0.77); less close correlation was obtained with the end-diastolic volume compliance (r = +0.67). These results demonstrate that the diastolic amplitude time index reflects interpatient differences in both relaxation ability and diastolic distensibility of the human left ventricle. Thus, this measurement provides an important new method for noninvasive evaluation of the overall function of the left ventricle during diastole.

Adolescent↗