Search PubMed⌕ Search

Biomedical subjects

M Kaltenbach

Publications and source records attributed to M Kaltenbach.

At least 55 records · Page 3Linked to original sources
PubMed1993

Recanalization of chronic arterial occlusions: low-speed rotational angioplasty. 5 years experience in peripheral and coronary vessels.

Chronic complete occlusions still represent the major technical limitation of percutaneous transluminal angioplasty, both in peripheral and coronary vessels. The clinical use of low-speed rotational angioplasty started in 1986 for the peripheral and in 1987 for the coronary arteries, and has already become part of the clinical routine in several centres. Up to now more than 350 patients with peripheral and 250 patients with coronary occlusions have been treated in Frankfurt; a multicentre questionnaire already contains information about 1,252 patients with peripheral vessel obstructions. In peripheral occlusions the acute success rate was more than 80% if low speed rotational angioplasty was used as the first attempt; after failure of conventional techniques still more than 60% of the vessels could be recanalized successfully. In addition to occlusions of the arteries of the lower limb, indications now may include the iliac artery and the subclavian artery. In each of the patients with chronic coronary occlusions an attempt with conventional techniques had failed before. Following a learning curve, which was also influenced by a better understanding of morphological preconditions, the acute success has now reached 70%. Both in patients with peripheral and those with coronary occlusions the technique turned out to be a safe procedure. Early angiographically documented long-term results in both indications are comparable with conventional balloon techniques. It is concluded that the use of low-speed rotational angioplasty (ROTACS) can improve the results of non-operative invasive treatment, both in peripheral and in coronary arteries.

Angioplasty↗
PubMed1993

[Does ST-elevation in stress ECG depend on the extent of collateral circulation?].

As a possible cause of exercise-induced ST-elevation in patients without myocardial infarction, a poor or absent coronary circulation to the poststenotic coronary segment was postulated. To check this thesis, we examined 10 patients (pts.) with ST-elevation, respectively, ST-depression and comparable coronary status (coronary score 12 vs. 12; mean stenosis diameter 86 vs. 85%) and exercise parameters (work load 150 vs. 137.5 Watts; exercise duration 2.8 vs 3.5 min) with regard to their collateral circulation. In the group with ST-elevation there were nine pts. with severe proximal stenosis of the left anterior descending artery (LAD) and one pt. with a stenosis in the middle third of the right coronary artery. The 10 patients with ST-depression had a proximal stenosis in the LAD. The extent of the angiographically seen collaterals was equal in both groups. As a result, this study demonstrates that the size of the collateral circulation has no influence on the exercise-induced ST-elevation. The most plausible cause of exercise-induced ST-elevation is a functional decrease of the lumen of a severe stenosis.

Arrhythmias, Cardiac↗
PubMed1993

[Follow-up angiography after balloon dilatation of aortic isthmus stenoses in adults].

Between May 1985 and April 1991, 30 patients (seven females and 23 males) 14 to 54 years old (median, 25 years) underwent balloon angioplasty for unoperated native (n = 26) or recurrent postoperative (n = 4) coarctation of the aorta. 28/30 patients had systemic hypertension (RR > 140/90 mmHg). Dilatation of the stenotic segment could be achieved in 28/30 patients. The residual pressure gradient was > 30 mmHg in six patients. In 2/4 patients with recurrent coarctation the balloon had ruptured, while dilatation was successful in the other two patients. The mean diameter of the stenotic segment increased from 5.8 +/- 2.7 mm to 11.9 +/- 2.5 mm and the peak pressure gradient decreased from 61 +/- 18 mmHg to 20 +/- 13 mmHg. Complications were a small hemorrhagic pleural effusion in one patient and a groin hematoma in another patient. Clinical follow-up studies with retrograde catheterization of the aorta and angiography were performed in all 28 patients with dilated coarctation, 6 months to 6 years after the procedure, representing a total follow-up time of 72 (average, 2.6) patient-years. Multiple follow-up studies (n = 2-4) were performed in 17/28 patients. In one patient the first angiogram revealed aneurysm formation while a small bulge was seen in two others. Intra-aortic pressure measurements revealed a peak gradient of < 30 mmHg in 24/28 patients with a mean of 14 +/- 10 mmHg. The blood pressure was normal in 23/28 patients. In the other five patients whose pressure gradients were 7, 30, 30, 35, and 60 mmHg moderate hypertension persisted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Main branch stenosis after bypass operation. Indications for elective PTCA].

The unprotected left main stenosis still represents one of the contraindications of PTCA; recently developed concepts using percutaneous bypass techniques have not changed this fact so far. However, following bypass grafting the procedure can be done with low risk and may improve prognosis in case of later bypass occlusion. This study should clarify whether a higher rate of bypass occlusion is caused by postsurgical left main PTCA. From October 1981 to January 1991 a left main stenosis was dilated in 41 patients, 2 weeks to 12 years (mean 3.5 years) after bypass grafting. To date, 17/65 venous bypass grafts were already occluded, and 72.4% of the patients suffered from typical angina. In 34/41 patients (82.9%) PTCA was successful, severe complications (death, emergency surgery or myocardial infarction) did not occur and clinical improvement was achieved in 80% of symptomatic patients. Four months later, 26/34 patients (76.5%) had angiographic follow-up. Fifteen restenoses were found and a second PTCA was performed in 9/15. None of the venous bypass grafts, open at the time of the first PTCA, was occluded at follow-up. In one case PTCA of the left main stenosis turned out to be life-saving 7 years later because an occlusion of RCA- and LCX-bypasses occurred and the LAD graft showed a subtotal thrombosis. It is concluded that PTCA of left main stenosis after bypass grafting is a safe procedure and does not lead to a higher rate of venous bypass occlusions. A prognostic indication seems to be justified.

Adult↗
PubMed1992

[Lowering increased cholesterol--prolonging life?].

Epidemiologic surveys reveal a positive correlation between serum cholesterol levels and the incidence of coronary artery disease. Intervention trials demonstrated that a reduction of serum cholesterol by 1% results in a decrease of coronary non-fatal events by 2%. Fatal coronary events remain almost uninfluenced. On the other side, several intervention trials showed an excess mortality from non-cardiac causes in the therapy groups (i.e. malignant tumors, suicides, accidents). Thus, until now no prolongation of life expectancy could be verified by cholesterol lowering measures.

Cause of Death↗
PubMed1992

[Echocardiography findings in hypertrophic cardiomyopathies. Diagnostic value of different echocardiography procedures].

In the present paper, the contribution of TM 2D and Doppler echocardiography to the non-invasive diagnostic evaluation of hypertrophic cardiomyopathies is discussed. The selective use of various echocardiographic possibilities for the representation (visualization) of typical morphological and functional changes in hypertrophic myocardial diseases is described.

Cardiomyopathy, Hypertrophic↗
PubMed1992

[Reopening chronic arterial occlusions].

Chronic complete occlusions still represent the major technical limitation of percutaneous transluminal balloon angioplasty, both in peripheral and coronary vessels. The clinical use of low speed rotational angioplasty (ROTACS) started in 1986 for the peripheral and in 1987 for the coronary vessels, and has already become part of the clinical routine in several centers. Up to now, more than 300 patients with peripheral and more than 200 patients with coronary occlusions were treated in Frankfurt. In peripheral occlusions the acute success rate was more than 80% if used as the first attempt; after failure of conventional techniques still more than 60% of the vessels could be recanalized successfully. In addition to occlusions of the arteries of the lower limbs, the indication now includes the iliac artery and several other indications are under investigation. In each of the patients with chronic coronary occlusions an attempt with conventional techniques had failed before. Following a learning curve, which was also influenced by a better understanding of morphological preconditions, the acute success rate has now reached 70%. Both in patients with peripheral and those with coronary occlusions no deaths occurred. First angiographically documented long-term results in both indications are comparable to conventional balloon angioplasty. It is concluded that the use of low speed rotational angioplasty (ROTACS) can improve the results of nonoperative invasive treatment, both in peripheral and in coronary arteries.

Angiography↗
PubMed1992

[Long-term results of coronary angioplasty].

Recently published studies prove a favourable long term prognosis after coronary angioplasty, especially in patients with single vessel disease. PTCA success, progression of atherosclerosis, cardiac risk factors, extent of coronary artery disease and left ventricular function are determinants of the long term outcome. A lasting PTCA success can be assumed in patients without evidence of restenosis 6 months after PTCA. These observations are helpful criteria in the assessment of insurance risks.

Angioplasty, Balloon, Coronary↗
PubMed1992

[Drug therapy of hypertrophic cardiomyopathy].

INTRODUCTION: Hypertrophy of the myocardium occurring in hypertrophic cardiomyopathy (HCM) may affect different locations of the left ventricle. If the hypertrophy is sited in the region of the basal septum, obstruction of the left ventricular outflow tract (hypertrophic obstructive cardiomyopathy [HOCM]) occurs. characteristic of left ventricular function in HCM is hypercontractility and disordered diastolic relaxation. THERAPEUTIC APPROACHES: In the medical treatment of HCM, the calcium antagonists play a leading role. They improve relaxation and, through their negative inotropic effect, decrease the intraventricular gradient. Although beta-blockers reduce the gradient in outflow tract obstruction, they do not improve relaxation. In individual cases the use of diuretics and anti-arrhythmic agents may be necessary; in the case of atrial fibrillation the use of marcumar is recommended. CAUTIONARY REMARK: In the event of dental treatment or invasive diagnostic procedures being necessary, prophylactic measures against endocarditis should be initiated.

Adrenergic beta-Antagonists↗
PubMed1992

[Ventricular function in hypertrophic cardiomyopathy. Systolic and diastolic ventricular function].

BASIC CONSIDERATION: Hypertrophic cardiomyopathy is defined as a primary myocardial disease associated with a hypertrophic non-dilated left ventricle with no other heart or systemic disease that might lead to hypertrophy of the left ventricle. The leading symptoms are effort-associated angina and dyspnea, rapid fatigue, dizziness and syncope. MAIN POINTS DISCUSSED: The hemodynamic situation is characterized by a hyperdynamic systole and impaired diastole and left-ventricular filling. In the obstructive form, hypertrophy of the basal septum and an anteriorly moving mitral valve during systole result in an end-systolic reduction in the cross-section of the outflow tract associated with considerable intraventricular pressure gradients. Disturbances in the myocardial calcium metabolism are presently suspected to be causally involved in the diastolic function impairment.

Cardiomyopathy, Hypertrophic↗
PubMed1992

[Cholesterol--a marker for multiple risk factors? A comparison between coronary disease and coronary health].

Comparison was made in a cross-sectional study between 658 patients in whom coronary arteriography had shown (n = 304) or excluded coronary artery disease (CHD) (n = 354) and a clinically healthy group as controls (n = 1658), to assess possible risk factors. Patients aged 31-40 years with CHD had the highest total cholesterol levels (286 +/- 43 mg/dl) and the highest number of risk factors (3.6 +/- 0.9) compared to patients without CHD of the same age (204 +/- 30 mg/dl; 2.0 +/- 0.5) and healthy controls (216 +/- 45 mg/dl; 1.7 +/- 0.5) (P less than 0.001). In older patients with CHD, total cholesterol levels were lower (age group 61-70 years: 231 +/- 49 mg/dl), reaching about the same level as that of patients without CHD (232 +/- 54 mg/dl) or healthy controls of the same age (228 +/- 55 mg/dl). Furthermore, it was demonstrated that increased total cholesterol concentration can indicate the presence of other risk factors. It would thus appear that the level of total cholesterol in patients with CHD is decisively influenced by age and the presence of other risk factors.

Adult↗
PubMed1992

[Iatrogenic origin of pleural effusion. A rare complication of the central venous catheter].

CASE REPORT: A 47-year-old woman with unremarkable plain chest X-rays in whom the Seldinger technique was employed to place a central venous line via the jugular vein, a catheter-related pleural effusion developed. CONCLUSIONS: This case points up the need to exercise care when placing a central venous line, and suggests the need to use contrast medium for the radiological follow-up examination.

Acute Disease↗
PubMed1992

[Use of collagen in sealing of arterial puncture holes after heart catheterization].

Percutaneously introduced absorbable purified bovine collagen was used to plug the hole at the site of femoral arterial puncture in 50 patients (42 men, 8 women; median age 58 [22-75] after percutaneous coronary angiography (n = 32; heparin dosage 100 IU/kg) or transluminal coronary balloon dilatation (n = 18; heparin dosage 200 U/kg). Local bleeding ceased after compression of 4 min in 48 of the 50 patients. A pressure bandage was needed additionally in the other two. Bed-rest lasted for 1-24 (median 19) hours. A haematoma of more than 6 cm diameter developed in five patients, but required neither transfusion nor surgical intervention. 39 of the 50 patients were re-examined after a median of 39 days: all of them had had a small pain-free swelling for 2-6 weeks over the puncture site. One patient developed a deep-vein thrombosis one week after the procedure, in another fever occurred after the same period, lasting for two days. These early findings are encouraging. The method may significantly shorten the time of arterial compression and bed-rest, as well as reduce the risk of a large haematoma after arterial punctures.

Adult↗
PubMed1992

A word of caution: reopening chronic coronary occlusions.

Reopening of chronically occluded coronary arteries by angioplasty, initially considered a low risk procedure, may carry similar risks at PTCA of coronary stenoses. We report 3 cases with ventricular fibrillation or sudden death 2-4 days after reopening of 1- to 5-month-old coronary occlusions.

Aged↗
PubMed1992

Collagen application for sealing of arterial puncture sites in comparison to pressure dressing: a randomized trial.

One hundred patients undergoing routine diagnostic or interventional catheterization were randomly assigned to receive either percutaneously applied collagen (group A; n = 50) or conventional pressure dressing (group B; n = 50) for sealing of the femoral artery. Clinical variables were comparable in both groups. The heparin dose was 100 IU/kg in 30 patients and 200 IU/kg in 20 patients of either group. The average compression time was 4.3 min in group A and 42.3 min in group B (p < .001). Bleeding was not observed in group A but was observed in 6/50 patients in group B. The time to ambulation was 6.4 hr (range, 4-12 hr) in group A and 21.6 hr (range, 10-48 hr) in group B (p < .001). Hematomas with a diameter of > 6 cm developed in 4/50 patients in group A and in 11/50 patients in group B (p < .05). Blood-transfusions or surgical interventions were not required and there was no loss of ankle pulses in either group. In conclusion, percutaneously applied collagen reduced compression time and duration of bedrest after diagnostic catheterization and PTCA. Despite earlier ambulation, the incidence of bleeding was lower with collagen than with conventional pressure dressing.

Aged↗
PubMed1992

Long-term follow-up after percutaneous transluminal coronary angioplasty in patients with single-vessel disease.

Seven hundred ninety-eight patients with symptomatic single-vessel disease who underwent percutaneous transluminal coronary angioplasty (PTCA) between 1977 and 1985 were reevaluated by questionnaire 78 +/- 23 months after dilatation. Indication for PTCA was stenosis of > or = 70%, anginal symptoms, and objective signs of myocardial ischemia. The immediate success rate was 81.2%, and severe complications occurred in 7.1%, which included two fatal complications (0.3%). Repeat angiograms were performed in 582 of 648 patients who underwent successful dilatation and showed restenosis in 143 cases (24.6%). Within 1 year after the first dilatation, 586 patients had been successfully revascularized by PTCA (i.e., there was no evidence of restenosis or redilatation was successful), and 113 patients had undergone bypass surgery. The remaining 99 patients were treated medically if PTCA was unsuccessful or if restenosis (> or = 70%) that was not amenable to redilatation was present. The 8-year overall survival probability was 91.7%, and cardiac survival was 95.5%. The 8-year event-free survival probability was 52.7% for all patients: 62.5% in patients who had successful PTCA and 14.5% in patients who had unsuccessful PTCA (p = 0.0000). The cardiac survival probabilities of patients with lasting PTCA success at 1 year and of surgically treated patients were significantly better than those of patients who did not have successful revascularization (at 8 years 97.2% and 98.1% vs 88.9%; p < 0.04). Late events (> or = 1 year) occurred more often in patients who did not have successful revascularization compared with patients who had successful PTCA (at 8 years 57.9% were event-free vs 74.4%; p < 0.0001); even fewer late events were observed in surgically treated patients (at 8 years 88.2% were event-free; p < 0.004). Cox's proportional hazards regression analysis revealed left ventricular ejection fraction and revascularization status at 1 year as determinants of overall, cardiac, infarct-free, and event-free survival probabilities. At the time of reevaluation significantly more patients in the successful PTCA subgroup were still free of symptoms or had experienced improvement than patients in the bypass or medical subgroups (86.8% vs 68.9% and 59.5%, respectively; p < 0.0001), and more patients in the successful PTCA subgroup were still working (75.4% vs 53.3% and 56.9%, respectively; p < 0.001). We concluded that patients with single-vessel disease who have undergone successful dilatation have an excellent long-term prognosis with regard to survival, cardiac symptoms, and vocational status.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

Right ventricular volumes and hemodynamics after successful orthotopic heart transplantation. A comparison to coronary artery disease using thermodilution.

Only few data exist concerning right ventricular function in the chronic stage after cardiac transplantation. Therefore, we investigated hemodynamic and right ventricular volumetric data by a computerized thermodilution Swan-Ganz catheter in 17 patients (median age: 53, range: 18-63 yr) at a median of 24 (4 to 44) months after cardiac transplantation during rest and supine bicycle exercise. Myocardial biopsy showed grade one or less according to the classifications of Billingham. Sixteen patients with coronary artery disease, but without prior myocardial infarction, served for comparison. While angiographic left ventricular ejection fraction was nearly identical in transplant recipients [77 (60-92)%, median (range)] and in patients with coronary artery disease [78 (64-94)%], right ventricular ejection fraction was lower (p < 0.001) in patients after cardiac transplantation [37 (16-58)%] as compared to patients with coronary artery disease [56 (46-62)%]. In transplant recipients right atrial pressure was significantly higher both at rest [10 (2-18) mmHg] and exercise [18 (8-30) mmHg] than in patients with coronary artery disease [5 (1-11) and 8 (3-18) mmHg]. Pulmonary capillary wedge pressure behaved similar in both groups. To further evaluate reasons for right ventricular impairment, a correlation analysis was performed. This showed a negative correlation between right ventricular ejection fraction and the time interval after transplantation (p < 0.0002). However, there was no correlation between right ventricular ejection fraction and acute rejection or a rejection score. In conclusion, right ventricular function may be severely altered in transplant recipients, in contrast to an only slight impairment of left ventricular function.

Adolescent↗