[Does yoghurt gnaw at cardiac valves?]

A 22-year-old man with pre-existing aortic valve disease contracted acute lactobacillus endocarditis six weeks after a dental procedure despite adequate prophylaxis. We discuss the limitations of prophylaxis for infective endocarditis in use until the end of 2008 and describe the new updated guidelines. We also explain the treatment of lactobacillus endocarditis and speculate on possible health risks of the increasing use of lactobacillus-containing dairy products, especially in immune-compromised patients.

Successful conservative treatment of nontyphoid salmonella endocarditis involving a bioprosthetic valve

We report a first case of Salmonella enteritidis endocarditis involving a bioprosthetic aortic valve. Despite additional native tricuspid valve involvement, the clinical course was favorable using an antibiotic regimen of ciprofloxacin and netilmicin. Although Salmonella prosthetic valve endocarditis is considered an indication for surgical replacement of the prosthesis, this case indicates that prolonged treatment with fluoroquinolones may be an alternative provided that the hemodynamic situation is stable.

[Cardiac interventions in Switzerland]

For the year 1995, as for the previous 10 years, a survey of cardiac invasive and surgical procedures in Switzerland was carried out by a standardised questionnaire. At the 25 Swiss centres (10 public non academic, 10 private and 5 academic centres) a total of 11,198 coronary revascularisation procedures were performed, the majority of them (60%) by percutaneous transluminal coronary angioplasty (PTCA). Of all PTCAs, 89% were single vessel interventions. PTCA for ongoing infarction accounted for 6% of all PTCAs. The use of coronary stents has increased to 28% of all angioplasties. Other devices like directional atherectomy and rotablations have lost ground (41 cases). Thirteen interventions with intracoronary laser catheters were recorded. Among the new diagnostic tools, only coronary ultrasound has been used regularly (191 cases). Percutaneous balloon valvuloplasties (64 cases) and catheter closure of congenital shunt defects (32 cases) remained rare interventions. Procedure related mortality for PTCA was 0.7%, infarction occurred in 1.1% and emergency coronary artery bypass grafting (CABG) became necessary in 0.7%. For the first time, the total number of CABGs (4485) decreased. Among the 2077 non-coronary operations, 56% were performed for valve disease and 44% for congenital heart disease. Heart transplantation was performed in 44 patients. The majority of interventional catheter procedures were performed at the 5 university centres whereas the majority of CABGs were carried out at private centres. Four centres performed diagnostic procedures, exclusively. In-house surgical stand-by for PTCA was present in 17 of the 21 interventional centres.

[Quality assurance in invasive cardiology: Switzerland]

In Switzerland, since 1985 mortality and morbidity data concerning either diagnostic and therapeutical coronary catheterization have been annually collected and analyzed. All interventional centres of the country (1994: 5 universities, 9 private and 3 public non academic hospitals) delivered their respective data. While there was a marked increase in diagnostic catheterizations (1989: 11'197, 1994: 20'603) and PTCAs (1989: 1'976, 1994: 5'590), the incidence of procedure related myocardial infarctions, emergency coronary artery bypass graftings (CABG) and in-hospital deaths evolved as shown in table 1 (results separated for university and non-university centres). Procedure related myocardial infarction and emergency CABG rates in patients undergoing PTCA have dropped from 2.1% to 0.9% and 3.1% to 1%, respectively, within 5 years. In the same period of time, the incidence of myocardial infarction after PTCA slightly increased from 0.7% to 0.9%. The higher rates of infarction and death in university hospitals do not necessarily mean poor quality of treatment but may reflect a more complex patient population in these centres. Furthermore, as declaring complications tends to be influenced by the concern of a negative impact on referrals, our data probably underestimate the true complications rates. For future surveys we consider anonymous data presentation and per-sonal audits at the individual centres.

[Cardiac interventions in Switzerland in 1994]

As in the previous seven years, a survey of cardiac invasive, interventional and surgical procedures among the 25 Swiss centers was carried out in 1994 by a detailed questionnaire. The resulting data are presented per individual center and per university, private or public sector. The outstanding findings of the 1994 survey are: There is an ongoing increase in the use of coronary angioplasty. The rapid evolution of coronary angioplasty is predominantly due to an extension of indications towards simple cases since the percentage of multivessel angioplasties has remained low. More than half of all angioplasties have been performed immediately after the respective coronary angiography (ad hoc angioplasty). The use of coronary stents has increased steeply over the past three years. Other new devices like directional coronary atherectomy, rotablation and transluminal extraction have lost further ground. PTCA for ongoing infarction has remained exceptional, probably due to logistical problems. Among the diagnostic tools, only coronary ultrasound has been used regularly. Coronary as well as non-coronary surgery seem to plateau. Percutaneous balloon valvuloplasties remained rather rare interventions. Catheter closure of congenital shunt defects has joined the routine interventional procedures. The majority of interventional catheter procedures have been performed at the five university centers whereas the majority of coronary artery bypass graft interventions have been carried out at private institutions.

Effect of residential cardiac rehabilitation following bypass surgery. Observations in Switzerland

BACKGROUND

Cardiac rehabilitation in central Europe traditionally involves isolating patients in a residential idyllic setting where exercise is performed frequently but in a relatively unstructured fashion. Few studies have been performed on the effects of these programs among patients who have undergone bypass surgery. Recent data suggest that postbypass patients may enter these programs too soon after surgery or that exercise is not structured enough to distinguish the benefits of rehabilitation from those experienced by a control group.

METHODS

Forty-two male patients (mean age, 58 +/- 7 years) were divided into exercise and control groups approximately 1 month after undergoing bypass surgery. Exercise training consisted of 1 h of group walking twice daily, with the intensity stratified into four levels based on initial exercise capacity. Using a crossover design, patients in the exercise group participated in rehabilitation for 1 month, followed by 1 month of usual care, while control patients underwent the opposite sequence. At 1, 2, and 3 months, patients in both groups underwent pulmonary function testing and maximal ramp exercise testing using lactate and gas exchange analysis.

RESULTS

A main effect for maximal oxygen uptake was observed; significant improvements within each group occurred across each testing period (range, 5 to 13%; p < 0.05). However, there was no significant interaction between groups. Mean lactate levels throughout exercise were reduced within both groups (p < 0.01). A reduction in oxygen uptake for test 2 at the lactate threshold in the exercise group resulted in differences between groups in lactate, heart rate, and other gas exchange variables at this point.

CONCLUSION

Similar changes occur in the functional status of postbypass surgery patients regardless of their participation in the short but concentrated programs common in central Europe. This suggests that a significant spontaneous effect of healing occurs in the recovery phase after surgery. These programs may have greater efficacy if they began later after surgery, lasted longer, or were more structured, and studies are needed to determine their effect on psychosocial factors and return to work.

Endothelin-1 in pulmonary hypertension associated with high-altitude exposure

BACKGROUND

Endothelin-1 is involved in chronic pulmonary hypertension. Its role in acute pulmonary hypertension due to hypoxia in humans is not clear. We therefore studied the influence of hypoxia caused by exposure to high altitude on plasma endothelin-1 levels, arterial blood gases, and pulmonary arterial pressure in subjects taking nifedipine or placebo.

METHODS AND RESULTS

Twenty-two healthy volunteers were investigated at low altitude (490 m) and high altitude (4559 m). Arterial blood gases were analyzed immediately, endothelin-1 was measured by radioimmunoassay, and pulmonary artery pressure was assessed by Doppler echocardiography. After baseline investigations, the mountaineers were allocated in a randomized double-blind fashion to receive either placebo or nifedipine (20 mg TID) during rapid ascent to high altitude within 22 hours. Tests were repeated at the high-altitude research laboratories located in the Capanna "Regina Margherita" (Italy, 4559 m). Plasma endothelin-1 was increased twofold at high altitude (5.9 +/- 2.2 pg/mL compared with 2.9 +/- 1.1 pg/mL, P < .05), was inversely related to arterial PO2 (r = -.46, P < .001), and correlated with pulmonary artery pressure (r = .52, P < .002). At high altitude, arterial endothelin-1 was lower (4.3 +/- 1.6 pg/mL) than venous endothelin-1 (5.9 +/= 2.2 pg/mL, P < .001), indicating either predominant production in the venous vasculature or pronounced clearance in the pulmonary circulation. The calcium antagonist nifedipine, which lowered pulmonary artery pressure at high altitude (32 +/- 5 versus 42 +/- 11 mm Hg, P < .05), had no influence on plasma endothelin-1 levels. The administration of 35% O2 at high altitude normalized arterial PO2, tended to decrease endothelin-1, and decreased pulmonary artery pressure accordingly.

CONCLUSIONS

We conclude that plasma endothelin-1 is increased at high altitude, but whether or not it represents an important pathogenetic factor for pulmonary hypertension remains to be investigated.

[Localized pulmonary edema in the right upper lobe--an important differential diagnostic hint for acute mitral insufficiency]

Differential diagnosis of unilateral alveolar pulmonary infiltration includes various possibilities. Acutely developing mitral insufficiency, often without any prior cardiac symptoms, may be the cause of pulmonary edema localized exclusively in the right upper lobe. This unusual and often misinterpreted radiologic presentation is brought to attention by two case reports.

Nifedipine does not prevent acute mountain sickness

Nifedipine has been shown effective for prevention and treatment of high altitude pulmonary edema (HAPE). Because acute mountain sickness (AMS) and HAPE may share common pathophysiologic mechanisms, we evaluate the prophylactic effect of nifedipine on the development of AMS in 27 mountaineers not susceptible to HAPE. They were randomly assigned to receive in a double-blind manner either nifedipine or placebo during rapid ascent to 4559 m and a subsequent three-day sojourn at this altitude. Nine of 14 subjects on nifedipine and eight of 13 subjects on placebo felt ill at high altitude. Pulmonary artery pressures (PAP) estimated by Doppler echocardiography were significantly lower with nifedipine, but arterial PO2, oxygen saturation, and alveolar-arterial oxygen pressure gradient were not significantly different between groups at high altitude. This study demonstrates that lowering PAP has no beneficial effect on gas exchange and symptoms of AMS in subjects not susceptible to HAPE. Therefore, nifedipine cannot be recommended for prevention of AMS, and its use in high altitude medicine should be limited to prevention and treatment of HAPE.

[Neurological side effects following vaccination of early-summer meningoencephalitis. Case report and experiences of the Swiss Center for Adverse Drug Effects]

Two weeks after vaccination against tick-born encephalitis (TBE) a 69-year-old patient developed subacute myelo-polyradiculitis. The neurological symptoms subsided after a few weeks. Alerted by this observation, we scanned the database of the Swiss Drug Monitoring Center (SANZ) for similar case reports. Of twenty spontaneous reports 11 concerned neurological side effects closely related to TBE vaccination. We conclude that TBE vaccination is associated with substantial neurological side effects and should, therefore, remain restricted to individuals at high risk for TBE.

[Sudden death during mass running events in Switzerland 1978-1987: an epidemiologico-pathologic study]

Between 1984 and 1987 there were 7 cases of sudden cardiac death during organized mass runs in Switzerland, and between 1978 and 1987 there were 3 cases during the nine largest mass running events (total 8 cases of sudden death during the race). Based on numbers of participants in all events 1984-1987, or in the nine largest events 1978-1987, an incidence of 1 sudden death per 129,500 hrs. of running (95% confidence interval 1/62,500-1/263,000 hrs.), or 1 sudden death per 117,000 hrs. of running (1/45,000-1/311,000 hrs.) respectively, was estimated. This estimate is higher than the rate of 1 sudden death per 396,000 hrs. of noncompetitive jogging found in a study from the United States (Thompson et al.: J. Amer. med. Ass. 1982; 247: 2535-2538). The Swiss incidence of sudden cardiac death during organized mass runs was 50 to 1000 times higher than the incidence expected by chance alone (as estimated from national death register data). All 8 cases of the study were men, the younger four aged 23 yrs. on average (range 20-31 yrs.), the older four aged 49 yrs. (46-53 yrs.). Autopsy in three of the younger men identified hypertrophic cardiomyopathy in one instance whereas in the two other cases no plausible cause of death could be found. The two autopsies performed in older men both showed severe coronary heart disease. Only in 1 case out of the 8 were possible prodromal symptoms of the subsequent death, such as fatigue and nausea, observed, and the average prevalence of known cardiovascular risk factors was low. None of the 8 runners dying suddenly was completely untrained, but 6 out of 8 had only modest running experience, i.e. a low number of years of running. This study confirms that there is probably a clearly increased risk of sudden death during running events with a competitive character, but this acute elevation of risk should probably not be overstated in view of both its very low population - attributable risk and the important potential of regular exercise for overall coronary risk reduction and health promotion.