Reproducibility of automated pulse wave velocity measurement during exercise. Running head: pulse wave velocity during exercise.

Pulse wave velocity measurement is used as an index of arterial stiffness. The purpose was to evaluate the reproducibility of pulse wave velocity measurement at rest, during exercise and recovery from exercise, using an automated device. Twelve healthy young adults (mean age 22.0 +/- 3.1 yrs) underwent an upright submaximal cycle test on two separate occasions, one week apart. Pulse wave velocity, systolic and diastolic blood pressures and heart rate were assessed at rest, during the last 2 min of exercise and 10 min later. Pulse wave velocity was measured on the upper limb and the forearm by the cross-correlation function of photoplethysmography and Doppler signals. Brachial artery pulse wave velocity was calculated from upper limb and forearm pulse wave velocities. No significant difference was found on duplicate measurements of heart rate, systolic and diastolic blood pressures at rest, during exercise and recovery, showing that pulse wave velocity was measured under similar conditions. Coefficient of variation for upper limb and forearm pulse wave velocities ranged from 2.9 to 5.9% at rest and during recovery, and were respectively 2.9% and 8.3% during exercise. However, coefficient of variation for brachial pulse wave velocity was 7.7 and 10.3% at rest, 15.7% during exercise, and 5.8% during recovery. During exercise, pulse wave velocity measurements were satisfying, but indirect assessment of brachial artery pulse wave velocity showed poor reproducibility. Thus, upper limb and forearm pulse wave velocities may be used during exercise to assess the effect of training or drugs on arterial wall mechanical properties.

Postoperative exercise tolerance after aortic valve replacement by small-size prosthesis: functional consequence of small-size aortic prosthesis.

OBJECTIVES: The objective of this study was to determine whether a small-size valve prosthesis contributes to exercise intolerance, as assessed by VO2 measurement during an exhaustive cycle ergometer exercise. BACKGROUND: The determinants of exercise capacity after mechanical aortic replacement are not well known. The selection of small valve sizes has, however, been described as an independent predictor of exercise intolerance as assessed by exercise duration. Maximal oxygen uptake (VO2max) is a good index of exercise tolerance. METHODS: Fourteen patients were eligible, with a mean age of 62 +/- 6 years. Before surgery, the mean left ventricular ejection fraction (LVEF) was 73 +/- 8%. Two valve types with small diameter (19 to 21 mm) were used: Medtronic Hall and St Jude Medical. A healthy sedentary control group (n = 14) paired for age, weight and size was constituted. After one year of follow-up, cardiorespiratory tests were performed. In addition, the gradients through the prostheses were determined by continuous pulse Doppler at rest and immediately after the cardiorespiratory test. RESULTS The exercise tolerance was not significantly different between the control group and patient group: VO2 peak (21.7 vs. 20.4 ml/kg/min; p = 0.42), workloads (115 vs. 93 W; p = 0.13) and ventilatory parameters were similar. The mean and peak gradients at rest and during exercise were not correlated with VO2max. CONCLUSIONS: Valve replacement by small aortic prosthesis does not seem to be a factor of exercise intolerance as assessed by VO2max in patients without LVEF dysfunction before surgery.

[What is the place of bioresorbable vascular scaffolds in setting of ST-segment elevation myocardial infarction?]. / Quelle place pour les stents biorésorbables dans la prise en charge du syndrome coronarien aigu avec sus-décalage du segment ST ?

A 50-year-old woman was admitted for an inferior ST-segment elevation myocardial infarction; immediate coronary angiogram revealed a subocclusive stenosis of the right coronary artery. After optimal antithrombotic treatment, the type of stent could be discussed. The latest generation of drug-eluting stents showed excellent efficacy and safety in the long-term but has limitations such as potential chronic inflammation of the arterial wall and no recovery of vasoactive function. Bioresorbable vascular scaffolds, with complete resorption within several months, may reduce these limitations. Implantation of bioresorbable scaffold in the context of myocardial infarction may be interesting. However, very few studies are currently available in this setting. Preliminary results and perspectives are presented in this review.

Myocardial viability assessed by dobutamine echocardiography in acute myocardial infarction after successful primary coronary angioplasty.

Dobutamine echocardiography (5 and 10 microg/kg/ min) was performed in 40 patients 4 +/- 1 days after acute myocardial infarction reperfused by primary coronary angioplasty. The left ventricle was divided into 11 segments. Reversible myocardial dysfunction was indicated by a decrease in at least 2 grades in the total segmental score. Follow-up echocardiography was performed 2 months later. Contractile reserve was documented in 18 patients with dobutamine echocardiography (45%). Sensitivity, specificity, positive, and negative predictive value of dobutamine echocardiography in predicting improvement in contractile function at follow-up were 82%, 83%, 78%, and 86%, respectively. Negative predictive value was high in all dyssynergic segments (86%). Positive predictive value was higher in hypokinetic than in akinetic segments (73% vs 21%; p <0.05). Recovery of wall motion at follow-up was statistically associated with higher left ventricular ejection fraction (p <0.04), collateral blood flow before reperfusion (p = 0.007), and dobutamine responsiveness (p = 0.0001), and was more frequently observed in hypokinetic than in akinetic segments (p <0.05). Thus, low-dose dobutamine echocardiography accurately predicts the extent of irreversibly damaged myocardium early after successful direct coronary angioplasty in acute myocardial infarction.

Cardiopulmonary exercise testing. Determinants of dyspnea due to cardiac or pulmonary limitation.

The aim of this study was to bring to light new and simple criteria, obtained during cardiopulmonary exercise testing, in order to demonstrate in patients the cardiac or the pulmonary origin of a comparable exertional dyspnea. Forty male subjects were compared, who exercised with a 30-W/3-min protocol and were divided into three groups: the cardiac heart failure (CHF) group (n = 15), the chronic obstructive lung disease (COLD) group (n = 15), and the control group (n = 10). The two groups of patients differed totally from the control group concerning their spirometric values at rest and a clear inability during effort which was confirmed by all the studied cardiopulmonary parameters at maximal exercise. The CHF and COLD groups differed slightly concerning their maximum symptom-limited oxygen uptake, only when related to body mass (13.26 +/- 0.69 ml/kg/min in CHF group, 17.05 +/- 1.59 ml/kg/min in COLD group; p < 0.05), and concerning their maximum ventilatory equivalent for oxygen which tended to be higher in the CHF group in comparison with the COLD group (p = 0.082). Furthermore, and as foreseen, the two groups of patients clearly differed at maximum exercise concerning the ventilatory reserve respiratory parameter (49.73 +/- 3.18 percent in CHF group, 8.38 +/- 5.85 percent in COLD group; p < 0.01). On the other hand, they did not differ concerning cardiac parameters or those considered as such (maximum heart rate [HR], HR reserve, HR response, maximum O2 pulse measurement). While their maximum ventilation was similar in the CHF and COLD groups, a difference in adaptation during exercise was found by observing their breathing pattern. In the CHF group, this was demonstrated by a significantly lower breathing frequency at maximum exercise (31.24 +/- 1.53 beats/min vs 37.75 +/- 2.24 beats/min; p < 0.05) and a tidal volume that tended to be higher at maximum exercise (p = 0.077) and significantly higher at 60-W work load (p < 0.05). This work shows that the study of ventilatory reserve and breathing pattern during exercise testing allows one to discriminate if dyspnea on exertion in patients is due to cardiac or respiratory disease.

Combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after acute reperfused myocardial infarction.

OBJECTIVE: To evaluate the combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after myocardial infarction. DESIGN: Myocardial contrast echocardiography was performed in patients with acute myocardial infarction shortly after successful coronary reperfusion (TIMI 3 patency) by direct angioplasty. Collateral flow was assessed before coronary angioplasty, and contrast reflow was evaluated 15 minutes after reperfusion. The presence of contractile reserve was assessed by low dose dobutamine echocardiography (5 to 15 micrograms/kg/min) at (mean (SD)) 3 (2) days after myocardial infarction. Recovery of segmental function (myocardial viability) was evaluated by resting echocardiography at a two month follow up. The study was prospective. PATIENTS: 35 consecutive patients referred for acute transmural myocardial infarction. RESULTS: Contrast reflow was observed in 20 patients (57%) and collateral flow in 14 (40%). Contrast reflow and collateral contrast flow were both correlated with reversible dysfunction on initial dobutamine echocardiography and at follow up (p < 0.05). The presence of reflow or collateral flow on myocardial contrast echocardiography was a highly sensitive (100%) but weakly specific (60%) indicator of segmental dysfunction recovery. Simultaneous presence of contrast reflow and collateral flow was more specific of reversible dysfunction than reflow alone (90% v 60%). CONCLUSIONS: Combined assessment of reflow and collateral blood flow enhanced the sensitivity of myocardial contrast echocardiography in predicting myocardial viability after acute, reperfused myocardial infarction. The simultaneous presence of reflow and collateral blood flow was highly specific of recovery of segmental dysfunction.

Exercise tolerance in heart transplant patients with altered pulmonary diffusion capacity.

To test whether orthotopic heart transplant (OHT) patients with low pulmonary diffusion capacity have a greater limitation to exercise than OHT patients with normal pulmonary diffusion capacity, we investigated cardiorespiratory responses and blood gases in two groups of OHT patients, one with low (LdG) and the other with normal pulmonary diffusion capacity (NdG), during a graded exercise test. The results showed 1) significantly reduced peak power (P < 0.05), peak oxygen uptake (VO2, P < 0.001), peak oxygen pulse (VO2/heart rate, P < 0.01), peak minute ventilation (VE, P < 0.05), and delta PaO2 (peak PaO2 - rest PaO2, P < 0.05) in LdG versus NdG; 2) a nonsignificant decrease in peak heart rate in LdG (P < 0.13, P = 24%); and 3) significant increases in peak respiratory equivalent for oxygen (VE/VO2, P < 0.05) and delta P(A-a)O2 (peak P(A-a)O2 - resting P(A-a)O2, P < 0.05) in LdG versus NdG. No significant difference was found for PaO2 and PaCO2 at rest or at peak exercise between the groups. A strong correlation was found between pulmonary diffusion capacity (TLCO/VA) and peak VO2 (r = 0.81, P < 0.01); that is, TLCO/VA explains 66% of the variance in peak VO2. We conclude that OHT patients with decreased pulmonary diffusion capacity have a lower exercise tolerance than patients with normal pulmonary diffusion capacity. However, because of the lack of exercise-induced hypoxemia, diffusion abnormalities are not the main limiting factor for exercise tolerance in the low diffusion group.

Doppler echocardiographic evaluation of the Omnicarbon cardiac valve prostheses.

Comprehensive 2 D/Doppler examination of 98 patients (mean age 56), implanted between September 1984 and February 1991, with normally functioning aortic (n = 49) and mitral (n = 49) Omnicarbon valves (OC) were analyzed in order to characterize the normal hemodynamic profiles of the OC valves. The mean time from implantation was 36.4 months (range 6 to 78). The following parameters were assessed (average of 5 measurements): peak transvalvular velocity (peak V), peak instantaneous gradient (peak G), mean transvalvular gradient (mean G), effective aortic valve area (ef Va), modified aortic valve area (m Va), aortic permeability index (PI), mitral valve area (Mit Va). Doppler data were correlated to prosthetic sizes (ranging from 21-29 mm for aortic OC and from 23-31 mm for mitral OC). The study establishes normal Doppler hemodynamics for each size (especially in aortic position) of OC valves and shows excellent performance. Significant correlations between peak G, mean G, Pl, and prosthetic aortic valve size (AS) were moderate. By contrast there were strong relationships between AS and ef Va (r = 0.56, p < 0.001) or mVa (r = 0.55, p < 0.001). These data should be helpful to identify OC prosthetic dysfunction.

Successful conservative surgery of acute ascending aortic dissection occurring during coronary angiography.

We reported the case of an acute aortic dissection complicating right guiding catheter manipulation during engagement in the right coronary ostium. Despite absence of hemodynamic deterioration, dissection progressed rapidly from the sinus of Valsalva to the ascending aorta along its entire length. At surgery, performed in emergency, the aorta was not dilated and the aortic wall did not appear pathologic. Therefore conservative surgery was performed, consisting of suture of the aortic tear and incollage of the false lumen, with good immediate and mid-term results.

Enalapril in the treatment of mild-to-moderate heart failure in general medical practice: a prospective and multicentre study concerning 17,546 patients.

The objective of this study was to test the efficacy and tolerability of a precise dosage regimen of enalapril in general medical practice, in combination with conventional therapy, in patients with mild-to-moderate (NYHA classes II and III) congestive heart failure (CHF). 17,546 patients were prospectively included in this multicentre study. After three months of treatment with enalapril, 53.9% of patients were asymptomatic (NYHA Class I) and 75.1% of patients improved by at least one class in the NYHA classification. 64.6% of patients reached maintenance dosage of 20 mg/day of enalapril and mean daily dosage for all patients was 16 mg. Outcome of functional symptoms according to NYHA class was more favourable with maintenance dosages of 15 and 20 mg/day of enalapril than with maintenance dosages of 5 and 10 mg/day of enalapril. Clinical and laboratory safety was good with low rates observed of the main adverse events: cough (1.74%), hypotension (0.34%), postular hypotension (0.30%), dizziness (0.31%) and hyperkaliema (0.13%); 1.4% of patients dropped out of the study because of such events. This extensive and open study confirms, in general medical practice, the feasibility, efficacy and tolerability of a dosage regimen of enalapril, which has been previously determined in controlled studies performed in specialized medical centres, for treatment of mild-to-moderate heart failure.

[Electrocardiographic aspects of sinoatrial block]. / Les aspects électrocardiographiques du bloc sino-auriculaire.

There are many electrocardiographic changes in sinoatrial block. Only 2nd and 3rd degree blocks can be analysed on surface recordings. However, they manifest themselves by pauses, the descriptions of which are rich and varied. They also vary according to the circumstances of apparition and the escape rhythms which accompany them. Related ECG changes such as chronotropic insufficiency or carotid sinus syndrome have been described. However, their significance is not univocal and only a precise analysis of the ECG recordings allows correct interpretation of the clinical and paraclinical signs and the institution of appropriate therapy.

[Role and significance of cytokines in the development of cardiac insufficiency]. / Rôle et signification des cytokines au cours du développement de l'insuffisance cardiaque.

The hypothesis of immune and inflammatory activation occurring during chronic cardiac failure, capable of maintaining the disease, is supported by many experimental and clinical trials. Plasma cytokines levels, particularly the tumour necrosis factor alpha (TNF alpha), are raised at advanced stages of the disease, especially in cachectic patients. The correlations with other, more traditional markers, especially neurohumoral, are not very close, probably suggesting different mechanisms. Cytokines are a group of very different molecules with multiple, non-specific, and even beneficial effects. However, the lack of regulation in severe cardiac failure may lead to deleterious effects on the heart. The experimental effects of TNF alpha (mini-pumps, transgenic animals) include features of myocarditis, chamber dilatation and contractile dysfunction. Large scale therapeutic trials of long acting TNF alpha antagonists could confirm the "inflammation hypothesis" of mutual interaction between cardiac failure and the production of cytokines.

[Ventricular fibrillation and defibrillation; electrophysiological bases and clinical applications]. / Fibrillation et défibrillation ventriculaires; bases électrophysiologiques et applications cliniques.

During sinus rhythm, the successive responses to the application of electrical stimuli of increasing intensity during the vulnerable period are cardiac stimulations followed by repetitive ventricular responses and then ventricular fibrillation. An impulse of even greater intensity is not followed by ventricular fibrillation (shock at the upper limit of vulnerability) suggesting that defibrillatory shock is effective only when it does not reinduce fibrillation. Two other hypotheses are also proposed in fibrillation, that of critical mass and that of extension of the refractory periods, in particular after biphasic shocks. Clinically, the measurement of the threshold of defibrillation is difficult as it is a random process which does not obey the all or nothing principle. Ideally, a graph of efficacy versus energy should be constructed but this is only possible under experimental conditions. The effects of different antiarrhythmic drugs have been studied in this manner; in general, the sodium channel blockers improve the energies of defibrillation.

[Late cardiac tamponade by localized compression of the left cavities after heart valve surgery. Apropos of 2 cases]. / Tamponnade tardive par compression localisée des cavités gauches après chirurgie valvulaire. A propos de 2 cas.

The authors report two cases of left cardiac failure occurring three and ten months after aortic valve replacement. Echocardiography established the diagnosis of localized compression of left heart chambers by hemopericardium. Surgical drainage dramatically improved patients with a follow-up of 4 years and 18 months. The authors emphasize the interest of left thoracotomy for drainage and discuss the etiology.

[Low-dose dobutamine echocardiographic assessment of reversible contractile dysfunction (myocardial stunning) after myocardial infarction]. / Evaluation par l'échocardiographie dobutamine à faible dose de la dysfonction contractile réversible (sidération myocardique) après infarctus du myocarde.

Low dose (5 to 10 micrograms/min) dobutamine echocardiography was used to predict the presence of reversible contractile dysfunction (myocardial stunning) after myocardial infarction successfully revascularised in the acute phase of primary angioplasty. The investigation was undertaken in 40 patients, 4 +/- 1 days after inaugural myocardial infarction. The left ventricle was divided into 16 segments. Viable myocardium was diagnosed when the initial regional wall motion score decreased by at least 2. Resting echocardiography was performed at 2 months to evaluate the effective recovery of regional wall motion (myocardial viability). The presence of contractile reserve was documented by dobutamine echocardiography in 18 patients (45%). The sensitivity, specificity and positive and negative predictive values of dobutamine echocardiography for the diagnosis of myocardial viability were 82, 83, 78 and 86% respectively. The negative predictive value was high in all dysnergic segments (86%). The positive predictive value of the investigation was however higher in hypokinetic than in akinetic segments (73 vs 21%; p < 0.05). The recovery of regional wall motion during follow-up was statistically related to higher initial left ventricular ejection fraction (p < 0.04), the presence of angiographically documented collateral circulation before revascularisation (p = 0.007), the contractile response to dobutamine (p = 0.0001) and was observed more frequently in hypokinetic than in akinetic segments (p < 0.05). These results show that low-dose dobutamine echocardiography is a sensitive and specific investigation for predicting irreversible myocardial damage after successful primary angioplasty in acute myocardial infarction. However, even in the absence of residual coronary stenosis, the presence of viable myocardium is only identified specifically in hypokinetic segments.

[Transient entrainment of tachycardia]. / L'entraînement transitoire des tachycardies.

Transient entrainment of tachycardia by pacing at a faster rate corresponds to its acceleration with return to sinus rhythm either when the pacing is interrupted or when the pacing rate is slowed. It conforms to strict criteria detectable either on the surface electrocardiogramme (constant fusion, progressive fusion, change of morphology before termination of a tachycardia) or on selective endocavitary recording when entrainment is hidden. The phenomenon described by Waldo in 1977 in atrial flutter is found in all reentrant tachycardias. It is currently being studied in ventricular tachycardia. The electrophysiological concept is useful because it facilitates the understanding of the mode of termination of tachycardia by stimulation and the localisation of zones for destruction during ablation.

[Floating thrombus in the right atrium and severe pulmonary embolism. Value of intravenous thrombolysis]. / Thrombus flottant de l'oreillette droite et embolie pulmonaire grave. Intérêt de la thrombolyse intraveineuse.

Mobile right atrial thrombi carry a high risk of pulmonary embolism which may be massive and are a medical emergency. Although surgery is commonly indicated, treatment with intravenous thrombolytics is an alternative and was successful in 4 out of 6 cases reported by the authors. Six patients, admitted for severe pulmonary embolism confirmed by pulmonary scintigraphy (6 cases) and by angiography (2 cases), underwent echocardiography which demonstrated a mobile right atrial thrombus. One patient was operated as an emergency and died immediately afterwards. Another, treated with heparin because of contraindications to surgery and thrombolysis had a recurrent fatal pulmonary embolism. In the other four cases, intravenous thrombolytic therapy was started immediately after echocardiography with 250,000 IU of streptokinase in 30 minutes, followed by 100,000 IU per hour for 48 to 72 hours associated with heparin 300 to 500 IU/kg/day. The biological efficacy of the treatment was confirmed in all cases (fibrinogen < 1 milligram; TCA > 60 s). A clinical improvement with improved blood gases was rapidly obtained in all 4 cases. The thrombus had totally disappeared at control echocardiography 8 to 12 hours after the initial examination. There were no complications, in particular no haemorrhages. After 6 months' follow-up, the outcome was good with oral anticoagulants (4 cases) associated with implantation of a caval filter in 1 case. Thrombolysis seems to be an effective alternative to surgery as there four cases demonstrate.

[Doppler color echocardiography in the diagnosis of 4 septal perforations complicating anterior myocardial infarction]. / Apport de l'échocardiographie-doppler couleur dans le diagnostic de quatre perforations septales compliquant un infarctus antérieur du myocarde.

The 4 cases reported here are meant to illustrate the value of colour doppler-echocardiography in the diagnosis of ventricular septal rupture consecutive to an anterior myocardial infarction. With this method, the examination begins with colour doppler ultrasound superimposed on two-dimensional echocardiographic images and is completed by pulsed and continuous wave doppler velocimetry. In all 4 patients an abnormal colour doppler flow was visualized from the outset; it started in the left ventricule and crossed the ventricular septum to enter the right ventricule, thus confirming the diagnosis and locating the septal defect. This abnormal flow was easy to recognize. On the apical "4 cavity" projection it followed a semi-circular anti-clockwise course which occurred at each cardiac cycle. The flow was red at first in presystole at the apex of the left ventricule; it became blue in pre- and middle-systole while traversing the septum, then mosaic-like in middle- or end-systole around the septal defect on the right ventricular side, and finally blue again in pre-diastole within the right ventricle. The blue trans-septal flow persisted at least up to pre-diastole. The diagnosis of septal rupture was confirmed at surgery in 3 cases and at right heart catheterization in 1 case. Colour doppler-echocardiography is a simple, efficient and rapid method, superior to contrast echocardiography or pulsed doppler alone, for direct real-time visualization of the shunt. It makes the septal defect easy to locate, and it avoids invasive exploratory manoeuvres in cases where surgery is contra-indicated and/or when coronary angiography is not mandatory.

[Transesophageal echocardiography in cardiac and paracardiac tumors. A multicenter study]. / Apport de l'échocardiographie transoesophagienne au cours des tumeurs cardiaques et paracardiaques. Etude multicentrique.

A multicentre study was undertaken to determine the diagnostic value of transoesophageal echocardiography (TOE) in tumours of the heart and pericardium. Forty-five cases were recensed: 24 myxomas, 1 fibroma, 1 hydatid cyst, 2 lymphomas, 3 sarcomas, 1 pleuropericardial cyst, 1 branchogenic cyst and 12 cardiac metastases. The diagnosis was made in all 45 cases by TOE but only in 35 cases by conventional transthoracic echocardiography which failed to recognise 2 myxomas, 1 hydatid cyst, 1 sarcoma, 2 paracardiac cysts and 4 cardiac metastases. The site of the tumour was identified 45 times by TOE compared with only 12 times by transthoracic echocardiography. However, the anatomical investigation of mediastinal tumours requires complementary computerised tomography. Moreover, TOE, like all other imaging techniques, is unable to predict the benign or malignant nature of the tumour, 1 leiomyosarcoma having been confused with a myxoma.

[Clinico-pathological polymorphism of hypertrophic cardiomyopathy in echocardiography]. / Polymorphisme anatomo-clinique de la cardiomyopathie hypertrophique en échocardiographie.

An echocardiographic Study of 322 adults (age: 40 +/- 16 years), belonging to 20 families with hypertrophic cardiomyopathy (HCM), was undertaken. Affected subjects had a LV diastolic wall thickness > 13 mm. The patients were classified according to the distribution of left ventricular hypertrophy (LVH) and by Maron's classification: 189 subjects were normal, 127 were affected and 6 could not been classified. By Maron's classification: 3% were type I, 33% were type II, 58% were type III and 6% were type IV. LVH was asymmetrical in 95% of cases (septum/posterior wall ratio > 1.3). The familial distribution of LVH of the 4 families in which HCM was genetically related to different loci (chromosome 11, 14 exon 13, 14 exon 8, fifth locus); the LVH was analysed from two short axis LV parasternal views and each plane was divided into 5 segments. The distribution of LVH was said to be identical between two first degree relations when all the same segments were affected, similar when they differed by only 1 or 2 segments and different when they differed by 3 or more segments. In the 26 pairs studied, LVH was identical in 2/26 (8%), similar in 11/26 (42%) and different in 13/26 (50%). Familial HCM usually gives rise to asymmetrical LVH affecting the septum and free wall. An identical distribution in 50% of affected first degree relatives.