[Scientific research in family medicine: practitioners' experience, barriers and needs]. / Recherche scientifique en médecine de famille: expériences, barrières et besoins des praticiens.

Scientific data from family medicine are relevant for the majority of the population. They are therefore essential from an ethical and public health perspective. We need to promote quality research in family medicine despite methodological, financial and logistic barriers. To highlight the strengths and weaknesses of research in family medicine in the French-speaking part of Switzerland we asked practitioners from this region to share their experience, critics and needs in relation to research. This article summarizes their contribution in light of the international literature.

Real-time multiplex PCR assays for reliable detection of Clostridium perfringens toxin genes in animal isolates.

Typing of Clostridium perfringens strains by PCR-based determination of toxin genes proved to be a reliable method for diagnosis of enterotoxaemia in various animal species. We report the establishment and validation of three real-time fluorogenic (TaqMan) multiplex PCRs for the detection of C. perfringens alpha-, beta-, beta2-, epsilon-, entero- and iota-toxin genes. The composition of the PCRs was chosen with regard to robustness of the assays and in order to increase sensitivity compared to the conventional simplex PCRs. The combination of probe dyes selected for the real-time assays (FAM/TAMRA, Cy-5/BHQ-2 and VIC/TAMRA) as well as the designation of the chromosome-borne alpha-toxin as internal positive control allowed the creation of highly specific and sensitive, as well as time and cost effective PCRs. One hundred and three strains of C. perfringens isolated in Switzerland derived from clinical or suspected cases of enterotoxaemia in 10 different animal species were tested. The toxin genotypes were in agreement in both the conventional PCRs and the newly designed multiplex PCRs. Furthermore, the real-time PCR carried out as simplex allows to quantitate the copy numbers of plasmid-borne toxin genes in relation to the chromosomally located alpha-toxin gene.

[What do we actually know about out-of-hospital cardiac arrest?]. / Arrêt cardiaque extrahospitalier: la situation actuelle.

Each year at least 300,000 people in the United States and 8000 to 10,000 people in Switzerland suffer from out-of-hospital cardiac arrest, mostly due to ventricular fibrillation. Early defibrillation provides definitive treatment for most of cardiac arrest victims. Semi-automatic external defibrillators are easy to handle devices allowing to deliver an early electric shock and can be successfully used by lay people following minimal training. Newer strategies of defibrillation designed to respond faster to out-of-hospital cardiac arrest, including public access defibrillation, as well as improvement of each link of the chain of survival appears as the best strategy for the management of out-of-hospital cardiac arrest.

Teaching cardiac auscultation to trainees in internal medicine and family practice: does it work?

BACKGROUND: The general proficiency in physical diagnostic skills seems to be declining in relation to the development of new technologies. The few studies that have examined this question have invariably used recordings of cardiac events obtained from patients. However, this type of evaluation may not correlate particularly well with bedside skills. Our objectives were 1) To compare the cardiac auscultatory skills of physicians in training with those of experienced cardiologists by using real patients to test bedside diagnostic skills. 2) To evaluate the impact of a five-month bedside cardiac auscultation training program. METHODS: 1) In an academic primary care center, 20 physicians (trainees in internal medicine and family practice) and two skilled academic cardiologists listened to 33 cardiac events in 13 patients directly at bedside and identified the cardiac events by completing an open questionnaire. Heart sounds, murmurs and diagnosis were determined beforehand by an independent skilled cardiologist and were validated by echocardiography. Thirteen primary cardiologic diagnoses were possible.2) Ten of the physicians agreed to participate in a course of 45-minute sessions once a week for 5 months. After the course they listened again to the same patients (pre/post-interventional study). RESULTS: 1) The experts were the most skillful, achieving 69% recognition of heart sounds and murmurs and correct diagnoses in 62% of cases. They also heard all of the diastolic murmurs. The residents heard only 40% of the extra heart sounds and made a correct diagnosis in 24% of cases. 2) After the weekly training sessions, their mean percentage for correct diagnosis was 35% [an increase of 66% (p < 0.05)]. CONCLUSIONS: The level of bedside diagnostic skills in this relatively small group of physicians in training is indeed low, but can be improved by a course focusing on realistic bedside teaching.

[Left ventricular hypertrophy: a marker for patients at risk of arterial hypotension during stress echocardiography with dobutamine?]. / Hypertrophie ventriculaire gauche: un marqueur des patients à risque d'hypotension artérielle durant l'échocardiographie de stress sous dobutamine?

OVERVIEW: Arterial hypotension during stress echocardiography with Dobutamine (ESD) is an occasional complication with no prognostic value, but it sometimes necessitates termination of the investigation. The present study had the aim of elucidating the mechanism responsible for hypotension during ESD and proposing one or several markers for patients at risk for this complication. METHOD: One hundred and twenty consecutive patients referred for stress echocardiography (Dobutamine or cycloergometrine) were analysed. Arterial hypotension induced by Dobutamine was defined as a fall of more than 30 mmHg compared to the arterial pressure before the test or following the preceding level of Dobutamine. Concentric left ventricular hypertrophy (LVH) was defined as a left ventricular mass > 125 g/m2. RESULTS: Among the 89 patients undergoing ESD, 32 (35%) had LVH, 9 of whom (28%) had arterial hypotension, prompting termination of the examination in 4 patients. Among the 57 patients (65%) without LVH, only 2 (3%) had hypotension. All patients with LVH had normal left ventricular function at rest and excellent contractility under stress, with no sign of ischaemia. None of the 31 patients, 5 of whom had LVH, who underwent the test with cycloergometrine had hypotension. CONCLUSION: Hypotension occurring during ESD affects patients more often with LVH (p < 0.001) and excellent systolic function. We postulate that the vigorous contraction of the left ventricle with Dobutamine produces excessive stimulation of the cardiac mechanoreceptors inducing a reflex hypotension. LVH is therefore a marker for patients at risk of hypotension and effort echocardiography is an excellent alternative to this investigation.

Should functional cardiac murmurs be diagnosed by auscultation or by Doppler echocardiography?

BACKGROUND: For many years, cardiac auscultation has been the only available method for distinguishing between functional and organic murmurs; however, a more reliable differential diagnosis can now be achieved with Doppler echocardiography. The question remains as to whether a Doppler echocardiogram needs to be routinely recorded in the presence of a heart murmur or whether the auscultatory diagnosis of a functional murmur is sufficient. HYPOTHESIS: This prospective study attempts to answer this important question at a time when medical costs have to be curbed. METHODS: The three cardiologists involved in this study saw 516 new patients in their private practice over a 10-month period; of these, 321 (63.6%) underwent Doppler echocardiography. All patients underwent careful auscultation prior to echocardiography. At the end of their examinations, the cardiologists noted whether they considered the murmur to be of functional or organic origin. Minimal mitral or aortic regurgitations of short duration and low velocity occurring on non-thickened valves were considered functional. RESULTS: The results for cardiac auscultation and Doppler echocardiography were considered to be concordant, that is, both techniques diagnosed either a functional or organic murmur in 250 of 321 patients (77.9%). The results for cardiac auscultation and Doppler echocardiography showed a major discordance in just six cases (1.9%). All were mitral regurgitations of moderate severity. CONCLUSION: The prevalence of cardiac murmurs in the general population is very high. As echocardiography currently represents a significant proportion of cardiac medical expenditure, it would be wise to limit the use of this technique to essential indications. This study confirms that both cardiac auscultation and Doppler echocardiography possess important limitations. Nevertheless, it also shows that well-trained cardiologists can identify the vast majority of functional murmurs on auscultation. Better training of nonspecialist physicians in cardiac auscultation may help in containing medical expenses.

Imaging of the abdominal aorta during examination of patients referred for transthoracic echocardiography.

BACKGROUND: Screening for aneurysm of abdominal aorta (AAA) in the general population is costly and unrealistic, but examination of the abdominal aorta appears reasonable in a high risk cardiological population. METHOD: As the abdominal aorta is easily accessible to standard transthoracic echocardiographic equipment, we tested this hypothesis in 301 consecutively referred patients (182 men, 119 women, mean age 58.6 +/- 16.5 years) by imaging the abdominal aorta at the end of the cardiac examination. RESULTS: After exclusion of three patients operated on for AAA before, the native infrarenal segment most often involved in AAA was visualised in 297 out of 298 patients (99.7%), and the aortic bifurcation was seen satisfactorily in 285 of them (95.6%). The abdominal aorta was dilated (> or = 2 cm) in 44 patients (15%), all but one of whom were > 50 years old; 17 of these (5.7%) had AAA defined as segmental dilation with a maximum diameter of > or = 3 cm (15 men, 2 women, age 67.4 +/- surgical repair and one endovascular repair within one year after completion of the data collection. Their mean age was 70.1 +/- 7.9 years, ranging from 58 to 80 years. No significant surgical morbidity and no mortality was observed. CONCLUSIONS: Prevalence of dilative alterations of the abdominal aorta is high in cardiological patients. Visualisation during transthoracic echocardiography of the most important infrarenal segment is nearly always feasible (99.7%), including its bifurcation (95.6%). Since detection of life-threatening but asymptomatic AAA may save lives by offering safe elective surgical treatment or stenting, opportunistic examination of the abdominal aorta during routine transthoracic echocardiography, which involves little time and no additional cost, would appear to be highly effective and should be included in routine examinations, at least in patients over 50 years of age.

[Arterial hypertension and left ventricular hypertrophy: viewpoint of the cardiologist performing echocardiography]. / Hypertension artérielle et hypertrophie ventriculaire gauche: le point de vue de l'échocardiographiste.

Left-ventricular hypertrophy is the main cardiac consequence of systemic hypertension. Since it is an established, independent cardiovascular risk factor, its recognition is important. As the sensitivity of electrocardiography in this field is considered insufficient, echocardiography is the most widely used method for the determination of left-ventricular mass. In spite of its well-known limitations, we recommend applying the Penn convention using M-mode echo. In current practice we suggest including echocardiography in the diagnostic work-up of a hypertensive patient, provided that at least one additional cardiological argument is present-such as the suspicion of a structural or functional anomaly-since it generates not only left-ventricular mass but also a wealth of other information, particularly about the valvular as well as the systolic and diastolic left-ventricular function.

[Bicycle exercise echocardiography in the supine position: a simple and effective study method for the detection and localization of myocardial ischemia by the first consulted cardiologist]. / Echocardiographie à l'effort sur cyclo-ergomètre en position couchée: une méthode d'investigation simple et efficace, à la portée du cardiologue de premier recours pour la détection et la localisation de l'ischémie du myocarde.

Exercise echocardiography is increasingly used as an investigative technique, now that dynamic images can be captured digitally. Its equivalent reliability compared to scintigraphic methods has been demonstrated in a hospital setting. This study is an attempt to analyse its impact in daily practise. Standardized progressive stress was provided by bicycle ergometry in a supine position. Echocardiographic images of complete cardiac cycles were obtained in standard apical and parasternal short axial views before, during and after maximum effort and digitized for simultaneous analysis of synchronized images at rest and during exercise. 279 patients were studied (231 men, 48 women, mean age 61 +/- 10 years). Image quality was suboptimal in four cases. In the remaining 275 cases, ischemia was detected in 125 cases, the test was negative in 141 cases and doubtful in nine cases. Control by selective coronary angiography, as motivated by the clinical situation, was performed in 72 cases. In this particular group, exercise echocardiography showed 89% sensitivity, which is significantly higher than the figure of 63% recorded for conventional exercise testing (p < 0.0001). Exercise echocardiography by bicycle ergometer in a supine position is a valid, noninvasive investigative technique which can be used in an outpatient situation (feasibility 95%), since it is available on the spot. Its value appears greatest in cases where exercise ECG was not conclusive. A negative result enables the first consulted cardiologist to reassure the patient immediately, the favourable prognostic value of such a result having been demonstrated in the literature.

[Continuing importance of the clinical approach. Observations on a regional collaboration between general practitioners, internists and cardiologists]. / De l'importance conservée de l'approche clinique. Réflets d'une collaboration régionale entre généralistes, internistes et cardiologues.

The advent of high-tech diagnostic methods raises concerns nowadays about the value of the clinical approach and bedside diagnosis. This at least is the impression given by modern scientific literature, which rarely even mentions this part of examination of the patient. In order to define the actual role played by auscultation in the management of cardiological patients by the primary care physician, the records of 250 patients consecutively referred to a cardiologist are analyzed. The practitioner's initial clinical diagnosis is compared to the final cardiological diagnosis. Per referred patient, 1.76 specialized consultations were needed. In 64% of the cases only one such consultation took place. Initial diagnosis was correct in 80% of all cases, partly correct in 11% and incorrect in 9% of the cases. Out of the 64 cases of valvular diseases, 33 were initially correctly recognized by the physician. The cardiological investigation was also invasive in 6.5% of all cases, 4.5% of the patients eventually undergoing invasive or surgical treatment. Thus the great majority of the patients (93.5%) were managed by the primary physician with "first-line" cardiologist's support, which was often only occasional (only one specialized consultation in about two thirds of all cases). This highly independent and presumably cost-effective patient management by the primary care physician implies a high level of clinical skill. It stresses the outstanding importance of continuing teaching of the clinical approach and particularly of cardiac auscultation, which is still the best screening method for valvular heart disease.

Fatal road accidents caused by sudden death of the driver in Finland and Vaud, Switzerland.

We investigated the incidence of fatal traffic accidents caused by sudden incapacity of the driver due to cardiac and other illnesses. The retrospective analysis was gleaned from Finnish traffic accident data files from 1984-1989, and police records of traffic accidents, from Canton de Vaud, Switzerland from 1986-1989. The annual rates of all traffic fatalities per million inhabitants were 125 in Finland and 212 in Vaud. Sudden driver incapacity due to acute illness caused 1.8 and 7.3 automobile driver deaths annually per million inhabitants in Finland and in Vaud, respectively. The corresponding rates for all-cause traffic deaths were 326 and 423, for driver deaths 105 and 167, and for those due to driver incapacity 4.7 and 15.6. Sudden driver incapacity caused 1.5% of all traffic deaths in Finland, and 3.4% in Vaud. Probable cardiac arrest caused 2.1% of all drivers' deaths in Finland and 1.7% in Vaud, respectively. Deaths caused by professional drivers' sudden incapacity were responsible for 0.11% of all traffic deaths in Finland, and for 0% in Vaud. Old age and short mileage were associated with illness-caused accidents. Accidents caused by sudden incapacity of the driver are rare causes of traffic deaths and hard to foresee. While this report relates to all drivers, we suggest there should be individual risk stratification for professional drivers with heart disease. However, non-professional drivers who are elderly and who have symptomatic cardiac disease should limit their driving to short distances and at low speed.

[Complementary information from Doppler echocardiography in the electrocardiogram in the basic assessment of chronic coronary heart disease, especially following a myocardial infarct. Observations from an ambulatory cardiology clinic]. / L'apport complémentaire de l'écho-Doppler cardiaque à l'électrocardiogramme dans le bilan de base de la maladie coronarienne chronique, en particulier après un infarctus du myocarde. Reflets d'une consultation cardiologique ambulatoire.

In chronic ischemic heart disease, Doppler echocardiography (DE) at rest permits semiquantitative evaluation of scarring and remodelling processes, global ventricular function and, frequently, regional wall motion state. Late complications are detected, namely infarct expansion, true and false ventricular aneurysm, mitral insufficiency, thrombus formation, and associated valvular and aortic diseases are discovered. We studied 100 patients with known chronic coronary artery disease referred for noninvasive evaluation, including electrocardiogram (ECG) and DE. In all patients, the global left-ventricular function was satisfactorily assessable. In roughly two thirds of the documented infarctions. DE confirmed the ECG diagnosis and permitted a more precise diagnosis in the majority of them in terms of localization and/or dimension of the necrosis. In one third of the patients. DE clarified inconclusive ECG tracings. Thus, the baseline noninvasive investigation with ECG and DE is a potent tool in the management of chronic ischemic heart disease, serving as a guide to further investigation and to treatment adjustments.

[Is electrocardiographic diagnosis of left ventricular hypertrophy possible in the presence of an anterior hemiblock?]. / Le diagnostic électrocardiographique d'hypertrophie ventriculaire gauche est-il possible en présence d'un hémibloc antérieur?

The electrocardiographic diagnosis of left ventricular hypertrophy is often difficult because it is based on a large number of criteria which, even if taken on their own or as "scoring systems", have a poor sensitivity ranging from 10 to 60%. Some authors have shown that the diagnosis is easier--though at first sight this seems paradoxical--in the presence of altered ventricular depolarization. To verify this statement in the case of left anterior fascicular block, we tested the value of six different indices for the detection of left ventricular hypertrophy. We analyzed 100 patients with left anterior fascicular block and compared the six electrocardiographic indices with the echocardiographic reference method, using the formula of the Penn convention, to establish the left ventricular mass. The best index of the six was that of Gertsch: [S3+ (R+S) maximal precordial] greater than or equal to 30 mm. Its sensitivity was 74%, its specificity 69%, its positive predictive value 79% and its negative predictive value 63%. The other tested indices had a sensitivity of less than 45% with a specificity of more than 80%. Furthermore, Gertsch's index was of equal value in confirming the increased left ventricular mass due either to concentric hypertrophy or to dilated cardiomyopathy. This study therefore confirms that electrocardiographic diagnosis of left ventricular hypertrophy is even easier in the presence of left anterior fascicular block than in absence of altered ventricular depolarization. This result is of practical interest, the incidence of left anterior fascicular block being 1 to 5% in the general population and as high as 30% after the age of 80.

Subjective visual echocardiographic estimate of left ventricular ejection fraction as an alternative to conventional echocardiographic methods: comparison with contrast angiography.

Left ventricular ejection fraction (LVEF) is a measure of ventricular function with clinical and prognostic significance and can be reliably calculated with various M-mode and two-dimensional echocardiographic formulas in selected, good quality echocardiograms. Subjective visual echocardiographic estimate of LVEF is a potentially less time consuming and more widely applicable method. In order to test its reliability, we performed a prospective blind trial in 40 consecutive patients undergoing biplane contrast ventriculography (BCV), to compare the visual estimate of LVEF during a complete echocardiogram of three independent observers with (1) cubed M-mode formula, (2) Teichholz M-mode formula, (3) length-area method from the four-chamber view, and (4) Simpson's single plane formula. BCV was the reference method. The best correlation with BCV was obtained by visual estimate [r of the three observers, respectively = 0.75; 0.84; 0.81] and M-mode measurements [r (1) = 0.8; r (2) = 0.8], but the most sophisticated methods provided the poorest estimate [r (3) = 0.54; r (4) = 0.49]. All correlation coefficients improved when good studies, defined as a definition of the endocardial surface of more than 75%, were selected (n = 23), but the differences persisted. One observer systematically estimated higher values than the other two (Friedman's test, p less than 0.01) and this interobserver variability suggests that each echocardiographer should test himself against BCV in his lab in order to apply the visual estimate method reliably.

[Echocardiography of the right heart--unknown territory. Contribution of echocardiography and Doppler echocardiography to the study of the right heart]. / L'échocardiographie du coeur droit--cette inconnue! Apport de l'échocardiographie et de l'écho-Doppler à l'examen du coeur droit.

The aim of this study involving 700 echocardiographic examinations (echoes) was to evaluate the diagnostic impact of the method for right heart abnormalities. Among 200 two-dimensional echoes of a first series we found 23 abnormalities (11.5%): nine congenital malformations, seven pulmonary hypertensions, four cases of isolated right ventricular dilatation, two tricuspid regurgitations (TR), one right atrial myxoma. In four cases the abnormality was clinically unexpected. In a second series of 500 patients, consecutively subjected to a two-dimensional echo with pulsed-wave and continuous-wave Doppler, we found 119 regurgitations of right heart valves in 98 patients (20%): 35 TR and 24 pulmonary regurgitations (PR) secondary to pulmonary hypertension, 13 TR secondary to tricuspid valve prolapse, 16 TR and 11 PR as a part of polyvalvular disease; 10 TR and 10 PR were isolated observations. The examination technique and the echo signs of the principal abnormalities of the right heart are reviewed. In summary, we emphasize that right heart abnormalities are surprisingly frequent in routine echo investigations; therefore, complete study of all the right heart structures in every echo examination is mandatory.