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Biomedical subjects

O Bertel

Publications and source records attributed to O Bertel.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Possible future of the project for quality assurance of indications and outcome in interventional cardiology and gynecology].

In the last few years the basis for national guidelines for the indications of coronary angiography, coronary revascularisation and hysterectomy has been established. The guidelines have been published and are accessible to medical doctors and patients on the Internet using a database system called "Second Opinion System": http:/(/)sos.inf.ethz.ch Dissemination, implementation and validation of the guidelines will be of major importance in the near future. With reference to validation, the question remains whether the established guidelines are correct for the everyday treatment of patients. A suitable method of answering this important question is comparison between the appropriateness and necessity rates of the various indication groups, combined with outcome measurements. The Internet-based second opinion system (SOS) may be used for data collection in order to verify hypotheses. Because of the database architecture, only relevant information about the patients is collected via Internet, independent of time and place. In addition, the system allows users to evaluate their individual data, and special attention is given to data protection. The discussion about priorities in health care (rationing) will be increasingly important in the near future. The present project may offer a way of maintaining adequate access to health care services for patients. Therefore, the participation of as many institutions as possible in the project "quality assurance of indication and outcome in interventional cardiology and in gynaecology" is of great importance.

Cardiology↗
PubMed1999

A randomized evaluation of early revascularization to treat shock complicating acute myocardial infarction. The (Swiss) Multicenter Trial of Angioplasty for Shock-(S)MASH.

AIM: To test whether emergency revascularization improves survival in patients with acute myocardial infarction and shock. METHODS AND RESULTS: Patients with acute myocardial infarction and early shock were randomized either to undergo emergency angiography, followed immediately by revascularization when indicated, or to receive initial medical management. In five of the nine participating centres, patients with shock but not randomized were entered in a registry. Only 55 patients could be randomized. Of the 32 patients in the invasive group, 30 (94%) underwent early angiography, 27 (84%) PTCA, and one (4%) CABG. Twenty-two (69%) died within 30 days in the invasive group vs 18/23 (78%) in the medically managed group (ns, RR=0.88, 95% confidence interval 0.6-1.2). Among the registry patients, 24/51 were excluded from randomization solely because of patient or physician preference for the invasive approach: 23 (96%) of them underwent emergency angiography, 21 (88%) PTCA, and 12 (50%) died within 30 days. Among the remaining registry patients (n=27) only nine (33%) underwent early angiography, nine (33%) PTCA and 20 (74%) died. CONCLUSION: We failed to demonstrate that emergency PTCA significantly improves survival in patients with acute myocardial infarction and early cardiogenic shock. Because the study was stopped prematurely, due to an insufficient patient inclusion rate, a clinically meaningful benefit of early reperfusion may have been missed.

Aged↗
PubMed1999

Epicardial, biatrial synchronous pacing for prevention of atrial fibrillation after cardiac surgery.

About 30% of patients develop AF after open heart surgery. Biatrial synchronous pacing (BSP) has been shown to promote sinus rhythm in patients with paroxysmal AF refractory to drug therapy. We conducted a prospective, randomized study to test the effect of BSP via epicardial electrodes on the incidence of AF after heart surgery, as compared to conventional therapy. To apply BSP, we attached two epicardial electrodes to the right and one to the left atrium. Immediately following surgery, BSP was initiated in the AAI-Mode at a rate of 10 beats/min above the underlying rhythm (maximum 110 beats/min) and continued for 3 days, during which the rhythm was continually monitored. After 21 (age 63 +/- 9 years) of the planned 200 patients, the study was prematurely aborted because of the proarrhythmic effect of BSP: 6 of the 12 patients treated with BSP developed sensing failure (P amplitude < 1 mV), which provoked AF in 5 of these 6 patients. BSP was discontinued due to diaphragmal stimulation in two patients and due to ventricular stimulation by a dislocated left atrial electrode in one patient. Two patients in the control group (n = 9) developed AF. Using the available standard technology, BSP via epicardial electrodes is not suitable to suppress AF after heart surgery, primarily due to postoperative deterioration of atrial sensing and its profibrillatory effect. In patients requiring atrial pacing after heart surgery, sensing thresholds must be closely monitored to prevent induction of AF.

Atrial Fibrillation↗
PubMed1999

Dual chamber pacing with a single-lead DDD pacing system.

The successful application of single-lead VDD pacing during the last few years has generated the idea of single-lead DDD pacing. Preliminary data from several single-lead VDD studies attempting to pace the atrium by a floating atrial dipole are unsatisfactory, causing an unacceptably high current drain of the device. We studied the feasibility as well as the short- and long-term stability of atrioventricular sequential pacing, using a new single-pass, tined DDD lead. In eight consecutive patients (age 73+/-16 years) with symptomatic higher degree AV block and intact sinus node function, this new single-pass DDD lead was implanted in combination with a DDDR pacemaker. Correct VDD and DDD function was studied at implantation; at discharge; and at 1, 3, and 6 months of follow-up. At implant, the atrial stimulation threshold was 0.6+/-0.1 V/0.5 ms. During follow-up, the atrial pacing thresholds in different every day positions averaged 2.1+/-0.5 V at discharge, 2.9+/-0.5 V at 1 month, 3.8+/-0.4 V at 3 months, and 3.4+/-0.4 V at 6 months (pulse width always 0.5 ms). The measured P wave amplitude at implantation was 4.5+/-2.2 mV; during follow-up the telemetered atrial sensitivity thresholds averaged 2.1+/-0.3 mV. Phrenic nerve stimulation at high output pacing (5.0 V/0.5 ms) was observed in three (38%) patients at discharge and in one (13%) patient during follow-up; an intermittent unmeasurable atrial lead impedance at 3 and 6 months follow-up was documented in one (13%) patient. This study confirms the possibility of short- and long-term DDD pacing using a single-pass DDD lead. Since atrial stimulation thresholds are still relatively high compared to conventional dual-lead DDD pacing, further improvements of the atrial electrodes are desirable, enabling lower pacing thresholds and optimizing energy requirements as well as minimizing the potential disadvantage of phrenic nerve stimulation.

Aged↗
PubMed1999

Hospital transfer for primary coronary angioplasty in high risk patients with acute myocardial infarction.

OBJECTIVE: To investigate the feasibility, safety, and associated time delays of interhospital transfer in patients with acute myocardial infarction for primary percutaneous transluminal coronary angioplasty (PTCA). DESIGN AND PATIENTS: Prospective observational study with group comparison in a single centre. 68 consecutive patients with acute myocardial infarction transferred for primary PTCA from other hospitals (group A) were compared with 78 patients admitted directly to the referral centre (group B). MAIN OUTCOME MEASURES: Patient groups were analysed with regard to baseline characteristics, time intervals from onset of chest pain to balloon angioplasty, hospital stay, and follow up outcome. RESULTS: Patients in group A presented with a higher rate of cardiogenic shock initially than patients in group B (25% v 6%, p = 0.01) and had been resuscitated more frequently before PTCA (22% v 5%, p = 0.01). No deaths or other serious complications occurred during interhospital transfer. Median transfer time was 63 (range 40-115) minutes for helicopter transport (median 42 (28-122) km, n = 14), and 50 (18-110) minutes by ground ambulance (median 8 (5-68) km, n = 54). The median time interval from the decision to perform coronary arteriography to balloon inflation was 96 (45-243) minutes in group A and 52 (17-214) minutes in group B (p = 0.0001). In transferred patients (group A) the transportation associated delay and the longer in-hospital median decision time (50 (10-1120) minutes in group A v 15 (0-210) minutes in group B, p = 0.002) concurred with a longer total period of ischaemia (239 (114-1307) minutes in group A v 182 (75-1025) minutes in group B, p = 0.02) since the beginning of chest pain. Success of PTCA (TIMI 3 flow in 95% of all patients), in-hospital mortality (7% v 9%, mortality for patients not in cardiogenic shock 0% v 4%), and follow up after median 235 days was similarly favourable in groups A and B, respectively. Only one hospital survivor (group A) died during follow up. CONCLUSION: Interhospital transport for primary PTCA in high risk patients with acute myocardial infarction is safe and feasible within a reasonable period of time. Short and medium term outcome is favourable. Optimising the decision process and transport logistics may further improve outcome by reducing the total time of ischaemia.

Aged↗
PubMed1998

Short-term oral endothelin-receptor antagonist therapy in conventionally treated patients with symptomatic severe chronic heart failure.

BACKGROUND: The vasoconstrictor peptide endothelin-1 (ET-1) is important for increased vascular tone in patients with chronic heart failure, but the effects of endothelin-receptor blockade in addition to conventional triple therapy are unknown. METHODS AND RESULTS: Thirty-six men (mean age+/-SD, 55+/-8 years) with symptomatic heart failure (NYHA class III; left ventricular ejection fraction, 22.4+/-4.5%) despite treatment with diuretics, digoxin, and ACE inhibitors received, in a double-blind and randomized fashion, either additional oral bosentan (1.0 g BID; n=24) or placebo (n=12) over 2 weeks. Hemodynamic and hormonal (plasma ET-1, norepinephrine, renin activity, and angiotensin II) measurements were obtained before and repeatedly for 24 hours after administration of bosentan on days 1 and 14. Bosentan was discontinued in 1 patient with symptomatic hypotension, and 2 patients (bosentan group) declined hemodynamic investigations on day 14. Compared with placebo, bosentan on day 1 significantly decreased mean arterial pressure (difference from baseline over 12 hours [95% CIs], -13.9% [-16.0% to -11.7%]), pulmonary artery mean (-12.9% [-17. 4% to -8.3%]) and capillary wedge (-14.5% [-20.5% to -8.5%]) pressures, and right atrial pressure (-20.2% [-29.4% to -11.0%]). Cardiac output increased (15.1% [10.7% to 19.7%]), but heart rate was unchanged. Both systemic (-24.2% [-28.1% to -20.3%]) and pulmonary (-19.9% [-28.4% to -11.4%]) vascular resistance were reduced. After 2 weeks, cardiac output had further increased (by 15. 2% [10.8% to 19.6%]) and systemic (-9.3% [-12.3% to -6.4%]) and pulmonary (-9.7% [-16.3% to -3.1%]) vascular resistances further decreased compared with day 1. Heart rate remained unchanged. Plasma ET-1 levels increased after bosentan, but baseline levels of the other hormones were unchanged. CONCLUSIONS: Additional short-term oral endothelin-receptor antagonist therapy improved systemic and pulmonary hemodynamics in heart failure patients who were symptomatic with standard triple-drug therapy. Further investigations are warranted to characterize the effects of long-term endothelin-receptor antagonist therapy on symptoms, morbidity, and mortality in such patients.

Administration, Oral↗
PubMed1998

[Cardiogenic shock].

Cardiogenic shock (CS), defined as forward failure combined with systolic blood pressure < 90 mm Hg and reduced organ perfusion despite adequate volume loading, still has a grim prognosis with mortality rates of 80-100% if the causes are left untreated. The most frequent conditions underlying CS are acute myocardial infarction, acute and severe aortic or mitral incompetence, rapidly progressive dilatative cardiomyopathy and hypertrophic obstructive cardiomyopathy. Whereas correct conservative management by drugs and pacing may be life saving in the latter, the other conditions require early invasive management. Indications for cardiac surgery and circulatory assistance are given for mechanical complications leading to CS. In CS complicating myocardial infarction, comprehensive management with early invasive revascularization and intraaortic balloon pumping may result in improved survival compared with the disappointing outcome of medical treatment, including fibrinolysis. This strategy can be offered to the majority of infarct patients in CS, who are primarily admitted to hospitals not equipped for interventional cardiology or cardiac surgery. Between-hospital transfer of these patients for PTCA (or surgery) and advanced intensive care has been shown to be feasible and safe.

Hemodynamics↗
PubMed1998

[Acute myocardial infarct in Switzerland: results from the PIMICS Heart Infarct Register. PIMICS Project (Prospective Ischemia Myocardial Infarction Captopril Survey)].

The aim of the PIMICS project was to create, for the first time in Switzerland, a registry of data concerning epidemiology and therapy in patients hospitalised for acute myocardial infarction covering all regions of the country. During 1995/96 73 Swiss hospitals of all categories took part in the PIMICS project. The ratio between males and females in the 3877 registered patients was 2.6:1 (2791 men vs. 1086 women). Female patients were significantly older than males (70.4 +/- 12.0 years vs. 63.4 +/- 12.6 years; p < 0.0001). The prevalence of risk factors differed between men and women: significantly more women had hypertension or diabetes, whereas smoking was more prevalent in males. The median delay between onset of symptoms and arrival at the hospital was 5.5 hours. Thrombolysis and primary angioplasty were more frequently performed in men (40.4% vs. 31.2% in women, p < 0.0001, and 5.7% in men vs. 3.5% in women, p = 0.005 respectively). During the acute phase males were treated more frequently with betablockers. The overall in-hospital mortality was 9.1%. It was significantly higher in female patients (13.5% vs. 7.4% in men; p < 0.0001) and in patients with reinfarction (14.5% vs. 7.1%; p < 0.0001). The mean hospital stay was 12.6 +/- 5.3 days. Only 7.7% of all patients with acute myocardial infarction were discharged within 6 days. At discharge, 51.7% were treated with betablockers and 69.3% with aspirin; 44.8% received ACE-inhibitors and only 13.8% lipid-lowering drugs. Follow-up measures such as coronary angiography and/or angioplasty or bypass surgery were performed significantly more often in males (45.0% vs. 32.9%; p < 0.0001). Likewise, men were more frequently assigned to a rehabilitation program than women (38.2% vs. 32.9%; p = 0.0004). The pre-hospital delay in patients with acute myocardial infarction remains too long. Primary and secondary prevention should be intensified in high risk groups, particularly in females. Thrombolysis and primary angioplasty as mainstays of treatment in acute myocardial infarction are generally used too sparingly, especially in women. With such measures the hospital stay could be shortened further.

Adult↗
PubMed1998

[Mechanisms and prevention of restenosis after coronary angioplasty].

The success of PTCA is limited by late restenosis, which occurs in 30-50% of all cases, chiefly within the first six months after the intervention. Restenosis is due to the proliferation of smooth muscle cells and especially to overproduction of extracellular matrix in the arterial wall. The coronary intervention is followed by a not fully defined constrictive process of wound healing, so-called remodeling. Various alternative intervention techniques were investigated but did not show any clear advantage concerning restenosis compared to PTCA. Although the rate of restenosis is reduced by stent implantation, which hinders remodeling, the remaining intimal hyperplasia often leads to restenosis. In spite of promising results in animal models, to date no effective human pharmacological therapy has been found to prevent restenosis. To determine whether antioxidants, endovascular radiation or gene therapy show any benefit will require further, larger trials.

Angioplasty, Balloon, Coronary↗
PubMed1998

Recurrent myocardial infarction caused by a giant coronary aneurysm.

We report on a patient with a giant aneurysm arising from the right coronary artery leading to infarction due to a steal phenomenon. Emergency coronary angiography was performed. The orifice of the aneurysm was occluded by balloon catheter restoring blood flow and resolving ischemia. Aneurysmectomie was done subsequently. The patient recovered very soon, and the following course was uneventful. This case illustrates that occasionally causes other than usual coronary atherosclerosis may lead to acute coronary syndromes.

Adult↗
PubMed1998

Symmetric and asymmetric left ventricular hypertrophy in patients with end-stage renal failure on long-term hemodialysis.

BACKGROUND: Patients with end-stage renal disease on regular hemodialysis have an increased prevalence of left ventricular (LV) hypertrophy that is associated with morbidity and mortality. Asymmetric septal hypertrophy and impairment of LV outflow can occur in these patients and may contribute to adverse outcomes. More insight into the prevalence, extent, geometry, and promoting factors of LV hypertrophy is important. METHODS: An unselected group of 62 patients (31 women), aged 55 +/- 14 years, on maintenance hemodialysis was investigated by Doppler echocardiography. Eight patients with valvular heart disease were excluded from further analysis. We assessed prevalence of LV hypertrophy and asymmetric septal hypertrophy, as well as parameters of LV geometry and LV filling and outflow dynamics. RESULTS: Prevalence of LV hypertrophy was 65%. Patients were analyzed according to LV mass and geometry. Mean LV mass index was normal (105 +/- 17 g/m2) in Group 1 without LV hypertrophy (n = 19); it was markedly elevated in Group 2 (symmetric hypertrophy, n = 22) and Group 3 (asymmetric hypertrophy with systolic anterior movement of mitral valve, n = 7), and highest (191 +/- 54 g/m2) in Group 4 (asymmetric hypertrophy without systolic anterior movement of mitral valve, n = 6, p < 0.001). Age, body mass index, and duration of hypertension were associated with LV hypertrophy and asymmetric septal hypertrophy (p = 0.01). Group 3 with systolic anterior motion of mitral valve had the smallest end-diastolic LV diameters (p = 0.02); increased heart rates, and increased ejection velocities in the LV outflow tract (p = 0.03, and p = 0.005, respectively, vs. Groups 1, 2, and 4) which pointed to an impairment of LV outflow. CONCLUSIONS: Symmetric LV hypertrophy and asymmetric septal hypertrophy are frequent in patients on maintenance hemodialysis. Predictors for LV hypertrophy were age and body mass index, and, particularly for asymmetric septal hypertrophy, age and hypertension duration. Volume withdrawal during hemodialysis may lead to symptomatic hypotension due to dynamic obstruction in some patients with severe asymmetric septal hypertrophy.

Adult↗
PubMed1997

[After care of acute myocardial infarct: what are the 4 most important points?].

The variable prognosis after myocardial infarction necessitates an individual tailoring of follow-up treatment. Therapeutic decisions must be based on a complete risk stratification including assessment of persisting ischemia, left ventricular function, rhythmic instability and cardiovascular risk factor profile. High risk patients (prognostic indication) as well as symptomatic patients (symptomatic indication) should be referred for coronary angiography to assess the need for revascularisation procedures (PTCA, CABG). The individual risk profile also defines drug therapy for secondary prevention (not more than 3-4 drugs): anti-platelet agents or anticoagulation in every patient; beta blockers in all but the lowest risk group; ACE-inhibitors in heart failure or asymptomatic, substantial left ventricular dysfunction; liberal use of cholesterol-reducing drugs. Life style alterations should be encouraged in almost every patient. Information about the necessary measures to be taken upon occurrence of angina at rest or other cardiac symptoms must be repeatedly given to all patients.

Aftercare↗
PubMed1997

[Secondary prevention in chronic coronary heart disease].

To assess the quality of secondary prevention in patients with known coronary artery disease (CAD) we analyzed prospectively 278 consecutive patients on admission who were hospitalized for acute coronary syndromes (infarction 46%, unstable angina 54%). CAD was known in 155 patients (110 males: acute myocardial infarction 50, unstable angina 105; history of infarction 55%, chronic angina 41%, after CABG 13%, after PTCA 7%, coronary stenoses on angiography 6%). In these patients, aspirin was being administered in 58%, anticoagulation in 12%, betablockers in 43%, angiotensin converting enzyme inhibitors (ACEI) in 20%, and lipid lowering agents in 12%. Calcium blockers were given in 40% (nifedipine 8%). Patients with previous invasive diagnosis and treatment were more frequently treated with drugs of proven prognostic benefit than patients after myocardial infarction and patients with angina only, while overall cardiovascular treatment was similar. The respective rates of treatment were: for aspirin 78%, 60% and 39% respectively (p = 0.0005); for betablockers 59%, 46% and 24% (p = 0.004); for lipid lowering drugs 27%, 7% and 4% (p = 0.002). 12 of 19 patients with known congestive heart failure had ACEI. Only one fourth of dyslipidemic patients had lipid lowering drugs. We conclude that the prevalence of secondary prophylaxis in patients with known CAD is too low despite proven benefit, invasively treated patients having better prophylaxis.

Adrenergic beta-Antagonists↗
PubMed1997

[Splenic infarct, lactate acidosis, and pulmonary edema as manifestations of a pheochromocytoma].

The case of a 45-year-old woman with pheochromocytoma, who presented with severe abdominal pain and headache, diabetes mellitus, lactic acidosis and pulmonary edema, is described and discussed. Spleen infarction, not so far described as an ischemic complication of pheochromocytoma, was seen in computer tomography. After medical pretreatment with labetalol, a pheochromocytoma (2 x 2 cm) of the left adrenal gland was removed. The postoperative course was uneventful.

Acidosis, Lactic↗