Arrhythmogenic response to isoproterenol testing vs. exercise testing in arrhythmogenic right ventricular cardiomyopathy patients.

Aims: To compare the arrhythmic response to isoproterenol and exercise testing in newly diagnosed arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. Methods and results: We studied isoproterenol [continuous infusion (45 µg/min) for 3 min] and exercise testing (workload increased by 30 W every 3 min) performed in consecutive newly diagnosed ARVC patients. Both tests were evaluated with regard to the incidence of (i) polymorphic premature ventricular contractions (PVCs) and couplet(s) or (ii) sustained or non-sustained ventricular tachycardia (VT) with left bundle branch block [excluding right ventricular outflow tract VT]; and compared to a control group referred for the evaluation of PVCs without structural heart disease. Thirty-seven ARVC patients (63.5% male, age 38 ± 16 years) were included. The maximal sinus rhythm heart rate achieved during isoproterenol testing was significantly lower compared to exercise testing (149 ± 17 bpm vs. 166 ± 19 bpm, P < 0.0001). However, the incidence of polymorphic ventricular arrhythmias was much higher during isoproterenol testing compared to exercise testing [33/37 (89.2%) vs. 16/37 (43.2%), P < 0.0001]. Interestingly, isoproterenol testing was arrhythmogenic in all 15 patients in whom baseline PVCs were reduced or suppressed during exercise testing. During both isoproterenol and exercise testing, control group presented a low incidence of ventricular arrhythmias compared to ARVC patients (8.1% vs. 89.2%, P < 0.0001 and 2.7% vs. 43.2%, P < 0.0001, respectively). Conclusions: The incidence of polymorphic ventricular arrhythmias is significantly higher during isoproterenol compared to exercise testing in newly diagnosed ARVC patients, suggesting its potential utility for the diagnosis.

A useful and easy to develop combined stress test for myocardial perfusion imaging: Regadenoson and isometric exercise, preliminary results.

BACKGROUND: Regadenoson, a selective A2a receptor agonist, is a vasodilator increasingly used in myocardial perfusion imaging. Adjunction of isometric exercise is a simple method that could improve side effect profile while providing better image quality. METHODS: Patients undergoing SPECT MPI were prospectively enrolled in handgrip-Regadenoson (HG-Reg test, N = 20) and Regadenoson (Reg) stress test (N = 40). Investigator blinded to stress test analyzed clinical data and images. RESULTS: Heart rate (HR) increase was statistically higher in the HG-Reg group (27 vs 22 bpm, P = .019). Decrease in SBP was less frequent in the HG-Reg group than in the Reg group (55% vs 85.5%, P = .005), there were less drops >10 mmHg (45% vs 77.7%, P = .012). During stress testing, fewer subjects reported at least one side effect in the HG-Reg compared to Reg group (70% vs 92.5%, P = .021). Images were more often classified as good in the HG-Reg group (75% vs 52.5% in the Reg group, P = .25). CONCLUSIONS: Adjunction of handgrip exercise to Regadenoson administration is a well-tolerated and easy method, without loss of time. Furthermore, image quality seems to be better.

Peri-infarct ischaemia assessed by cardiovascular MRI: comparison with quantitative perfusion single photon emission CT imaging.

OBJECTIVE: To develop a new method for the cardiac MR (CMR) quantification of peri-infarct ischaemia using fused perfusion and delayed-enhanced images and to evaluate this method using quantitative single photon emission CT (SPECT) imaging as a reference. METHODS: 40 patients presenting with peri-infarct ischaemia on a routine stress (99m)Tc-SPECT imaging were recruited. Within 8 days of the SPECT study, myocardial perfusion was evaluated using stress adenosine CMR. Using fused perfusion and delayed-enhanced images, peri-infarct ischaemia was quantified as the percentage of myocardium with stress-induced perfusion defect that was adjacent to and larger than a scar. This parameter was compared with both the percent myocardium ischaemia (SD%) and the ischaemic total perfusion deficit (TPD). The diagnostic performance of CMR in detection of significant coronary artery stenosis (of ≥70%) was also determined. RESULTS: On SPECT imaging, in addition to peri-infarct ischaemia, reversible perfusion abnormalities were detected in a remote zone in seven patients. In the 33 patients presenting with only peri-infarct ischaemia, the agreement between CMR peri-infarct ischaemia and both SD% and ischaemic TPD was excellent [intraclass coefficient of correlation (ICC) = 0.969 and ICC = 0.877, respectively]. CMR-defined peri-infarct ischaemia for the detection of a significant coronary artery stenosis showed an areas under receiver-operating characteristic curve of 0.856 (95% confidence interval, 0.680-0.939). The best cut-off value was 8.1% and allowed a 72% sensitivity, 96% specificity, 60% negative predictive value and 97% positive predictive value. CONCLUSION: This proof-of-concept study shows that CMR imaging has the potential as a test for quantification of peri-infarct ischaemia. ADVANCES IN KNOWLEDGE: This study demonstrates the proof of concept of a commonly known intuitive idea, that is, evaluating the peri-infarct ischaemic burden by subtracting delayed enhancement from first-pass perfusion imaging on CMR.

[The ventilatory response in chronic heart failure population]. / La réponse ventilatoire chez le patient insuffisant cardiaque.

Symptom-limited exercise test with peak oxygen consumption measurement possesses a strong prognostic value in chronic heart failure. This parameter allowing notably the selection of patients for heart transplant. Nevertheless, sub maximal effort and beta blocker therapy tend to limit its prognostic value. The ventilatory response evaluated by the minute ventilation - carbon dioxide production (VE/VCO2) linear regression slope during effort is generally considered to be a significant predictor of mortality and hospitalizations in HF population. An enhanced ventilatory response is correlated with a poorer prognostic. In addition, this parameter is not influenced by the intensity of the effort neither by the betablocker therapy. But, physiological determinants are not clear yet. Aim of our study is to confirm the important place of the (VE/VCO2) slope in HF patient's evaluation.

A rare form of midventricular Tako Tsubo cardiomyopathy.

We report a case of a rare form of midventricular Tako Tsubo cardiomyopathy characterized by left ventricular angiography and cardiac MRI.

[Complete atrioventricular block following long term treatment with chloroquine]. / Bloc auriculo-ventriculaire complet après prise de chloroquine au long cours.

Antimalarial agents are routinely used in the management of connective tissues diseases and various skin disorders. Ophthalmologic, neurological and digestive side effects of antimalarial agents are well known. However, cardiac toxicity is uncommon. We report a 49-year-old patient, treated with chloroquine for 21 years for a systemic lupus erythematosus and a discoid lupus, who presented a complete atrioventricular block that required implantation of a cardiac pacemaker in emergency. This patient did not have significant cardiovascular past medical history. Investigations excluded known causes of atrioventricular block and chloroquine toxicity was diagnosed. This case report illustrates the cardiotoxicity of synthetic antimalarial agents. A regular cardiovascular monitoring (especially with electrocardiogram) could be useful in patients receiving long-term treatment with antimalarial agents.

[Comparative study of exercise-induced ischaemia in coronaropathy and aortic stenosis]. / Etude comparative de l'ischémie d'effort entre patients coronariens et patients atteints de rétrécissement aortique.

OBJECTIVE: To compare exercise and recovery data between a population of patients with proven CAD and patients with pure aortic stenosis (AS). PATIENTS AND METHODS: Exercise testing results (bicycle ergometry) of 45 patients with AS (34 men, 66+/-12 years, 56+/-20 mmHg peak-to-peak gradient and valve area 0.78+/-0.48cm2) were compared to exercise testing results of 50 patients with CAD (41 men, 65+/-9 years, greater or equal to 70% stenosis on one vessel in 62%, two vessels in 30%, three vessels in 8%). RESULTS: During exercise, 38% patients with AS and 82% patients with CAD had clinical symptoms. In the AS group, exercise duration was longer, heart rate (HR) was higher, maximal systolic and diastolic blood pressure were lower than in CAD group. The increase of systolic blood pressure was lower in the AS group (34+/-21 mmHg versus 47+/-27 mmHg, p<0.02). Maximal load achieved was not significantly different. Exercise ST depression appeared in 76% of AS group and 88% of CAD group (NS). No difference was found in ST depression, Detrano index and ST segment/HR slope. During recovery, no difference was found in HR variations. Clockwise rotation of the ST/HR recovery loop was more frequent in CAD group (35 patients versus 19 patients, p<0.001). CONCLUSION: Most of the exercise and recovery data are similar in patients with AS and CAD. Significant discriminating criteria were the increase of systolic blood pressure during exercise and ST/HR recovery loop.

Automated function imaging: a new operator-independent strain method for assessing left ventricular function.

BACKGROUND: Speckle tracking is a new technique based on pure 2D grayscale ultrasound acquisition allowing calculation of segmental strains. To facilitate clinical application, speckle tracking has been integrated into the most recent echocardiographic systems for quick, automated evaluation of left ventricular function (Automated Function Imaging, AFI). OBJECTIVE: To evaluate the feasibility, calculation time, accuracy and reproducibility of global longitudinal strain (GLS) from AFI in determining LV function in comparison to reference echocardiographic and angiographic methods-whatever the operator's experience. METHODS: Echocardiography was performed in 65 patients scheduled for cardiac catheterization using a Vivid 7 system. They were divided into 3 groups according to EF (>55%, 35< or =EF< or =55%,<35%). Image quality, global LV function parameters (ejection fraction, aortic flow, dp/dt) and segmental contraction were analyzed by one experienced operator and one beginner. GLS was obtained from apical 2, 3 and 4 chamber views. GLS was compared to both echocardiographic and angiographic EF, as well as to other echocardiographic parameters. RESULTS: GLS was obtained successfully in 97% of patients. Mean calculation time including correction of endocardial detection was less than 60 seconds. GLS was significantly different between the 3 groups, respectively -18.1+/-2.5%, -11.5+/-2.1% and -6.0+/-1.2% (p<0.01). Strong correlations were observed between GLS and LV function (r from 0.68 to 0.87) with a high level of reproducibility. No difference was observed between experienced and inexperienced operators. CONCLUSION: AFI is clinically applicable and an effective means of assessing LV function due to its short acquisition time, feasibility and accuracy, whatever the experience of the operator.

[The best of cardiac rehabilitation in 2006]. / L'essentiel de l'année 2006 en réadaptation cardiaque et cardiologie du sport.

The meta-analysis showing the benefits of physical training revisited: Taylor examined only the cardiac rehabilitation trials of exercise intervention alone (versus usual care) and demonstrated that cardiac mortality is 28 % reduced and exercise appears to have an independent mortality benefit. An economic evaluation of cardiac rehabilitation: a systematic review of 15 economic evaluations. Evidence to support the cost-effectiveness of supervised cardiac rehabilitation compared with usual care in myocardial infarction and heart failure was identified. But further well-designed trials are required. Pronostic value of some variables determined by exercise testing entering cardiac rehabilitation and after physical training. A beneficial effect of physical training versus usual care on BNP and neurohormones in patients with chronic heart disease. Patients on beta blockers after myocardial infarction: determination of a more accurate training heart frequency derived from the classical Karvonen's formula. The combination of trimetazidine with exercise training provides greater improvements in functional capacity, left ventricular function and the endothelium-dependent relaxation of the brachial artery than exercise training alone in patients with ischaemic cardiomyopathy referred for cardiac rehabilitation. Guidelines for resistance exercise after cardiac event: a new paradigm less restrictive, safe and efficient to accelerate patients' return to daily activities. Recommendations for participation in leisure-time physical activity and competitive sports for patients with ischaemic heart disease: the result of consensus among experts from the ESC study group of sports cardiology.

[Exercise test in athletes]. / Epreuves d'effort chez les sportifs.

The particularities of exercise tests in athletes concern mainly the exertion protocols adapted to their increased physical capacities and the interpretation of ECG tracing which can sometimes be very special at rest and also misleading during exercise. In the great majority of cases, the test used is both cardiac and pulmonary, in order to assess the aerobic capacities, the maximal aerobic power, and the determination of ventilation thresholds (programming and follow-up of training...). More infrequently, the test is used to detect cardiovascular diseases, especially during a longitudinal follow-up of high-level athletes, or to exclude it in case of cardiovascular symptoms, atypical resting ECG or even in case of suspicion of disease (arrhythmia, cardiac chamber hypertrophy or dilation at echocardiography). In more aged sportsmen (athletes masters), exercise tests performed are usually required for screening coronary heart disease. In this case the test protocols should be more adapted for screening than for the assessment of sportive capacities.

[Survey of cardiovascular risk assessment and the behaviour of a sporting population]. / Enquête sur les comportements et l'évaluation du risque cardiovasculaire dans une population de sportifs.

In order to better understand the risk factors and behaviour of a general sports population, a questionnaire was handed to 603 consecutive sportsmen of various disciplines during a specific sports medicine consultation and a half-marathon. Among the discovered risk factors, smoking was the most common (19.3% for the entire study population), predominantly in the youngest group (26%). A resting ECG had been performed very frequently within the previous year in those over 40 years (86.5%), but less often in the younger sportsmen (44.8%). An exercise test had also very often been performed in those aged over 40 years (69.2 vs 10.6%). Behaviour associated with cardiovascular risk was common. Undertaking physical activity while febrile (58%) and smoking just before or after exertion (13.1%) were widespread behaviours. This population appeared casual in its approach to possibly suspicious cardiac symptoms of exercise, particularly the females and paradoxically the subjects doing the most sport. Lastly, only a minority of sportsmen knew the telephone number for the emergency medical service (45%) or claimed to be competent at first aid (32%). This survey underlines a practice relatively in accordance with the recommendations for detecting cardiovascular pathology, but shows a failure of preventive education.

[Unusual cause of myocardial infarction]. / Une cause rare d'infarctus du myocarde.

The authors report the case of a woman with an acute myocardial infarction in whom coronary angiography performed a few hours earlier was completely normal. Transoesophageal echocardiography showed two thrombi in the left atrial appendage confirming the thromboembolic mechanism of this infarct.

[Bi-ventricular synchronous pacing and heart failure]. / Resincronizzazione ventricolare e insufficenza cardiaca.

After initial trials of conventional DDD pacing in dilated cardiomyopathies, the concept of multisite stimulation was introduced in 1994. This new indication of heart failure treatment is based on the correction of myocardial contraction and relaxation asynchronies. European pilot studies including few patients were followed by two multicenters randomized trials (MUSTIC and MIRACLE) that confirmed a significant improvement of functional capacity, quality of life and hemodynamic status. Intraventricular delay and QRS duration shortening seems to be the best predictor of clinical success. Patients with more depressed functional and hemodynamic status seems to benefit most from this therapeutic approach. Two studies (CARE HF and COMPANION) are still conducted which will provide further insight into the effectiveness in terms of prognosis of cardiac resynchronisation therapy in this patient population.

[Exercise tolerance tests in athletes, then what?]. / Tests d'effort chez les sportifs, et ensuite?

Exercise tolerance tests in athletes are usually performed to evaluate aerobic exertion capacity and to plan training. They are based on simultaneous measurement of expired gases (determination of ventilation threshold and of VO2max). They can also be used to seek a possible cardiovascular anomaly, particularly in case of clinical symptoms or anomalies on auscultation; findings based on electrocardiography (rhythm, repolarisation, etc.) and on blood pressure readings, however, can lead to suspicion of an early anomaly and direct complementary investigation.

[Prognosis and risk evaluation of postoperative coronary patients (PERISCOP). Methodology and study population characteristics]. / Pronostic et évaluation du risque chez le coronarien opéré (PERISCOP). Méthodologie et caractéristiques de la population incluse.

The aim of the PERISCOP study was to evaluate the predictive value of cardiological investigations performed after recent coronary bypass surgery with regards to cardiac event and mortality at one year. The treatment of lipid abnormalities was also analysed. This first article describes the methodology and patient characteristics at inclusion. This prospective national multicenter trial included 2065 patients (86% men) with an average age of 63.1 +/- 9.9 years. The number of diseased vessels was 2.6 +/- 0.6. Preoperative left ventricular function was normal (ejection fraction 60 +/- 13%). Revascularisation was complete in 73% of cases (22% of arterial grafts). The cardiological investigations were performed at Day 20 +/- 10 after surgery. The duration of exercise on stress testing was 429 +/- 170 seconds. It was positive or doubtful in 9% of cases. Ventricular arrhythmias were observed in 6.5% of cases. The blood pressure response was abnormal in 6% of cases. Holter monitoring showed a median number of ventricular extrasystoles over 24 hours of 44. Three per cent of patients had one episode of ventricular tachycardia and 7% had ischaemic episodes. The echocardiographic index of segmental contractility was on average 1.75 (ejection fraction: 52.6%). The lipid analysis performed at one month, under lipid therapy in 34% of cases, showed a total cholesterol level at 1.91 +/- 0.10 g/l, an LDL-cholesterol of 1.27 +/- 0.08 g/l. The therapeutic target (LDL-cholesterol < 1 g/l) was attained in 46% of cases with treatment and in 18% of cases without treatment.

[Rehabilitation modalities as a function of the severity of heart insufficiency]. / Modalités de la réadaptation en fonction de la gravité de l'insuffisance cardiaque.

After a review of the different central and peripherical factors limiting exercise capacity in chronic heart failure, the authors report the mechanisms of these increment with exercise training. The different indications for clinical training techniques of segmental training on a specific bench are discussed; but it appears that both aerobic and repetitive weight programs seem to have short term favorable and complementary effects.

[Prognostic evaluation of silent ischemia during exercise in patient with recent infarction. Italian multicenter study. SMISS Group]. / Evaluation du pronostic de l'ischémie silencieuse à l'effort chez des patients avec infarctus récent. Etude italienne multicentrique. Groupe SMISS.

AIM: The aim of the Multicenter Silent Ischemia Study (SMISS), co-ordinated by the Italian Working Group on Cardiac Rehabilitation, was to evaluate prospectively, the prognostic significance of silent myocardial ischemia during exercise testing in patients with proven ischemic cardiac disease. METHODS: Over a period of six months 4389 consecutive patients performing a maximal symptom-limited exercise testing, after drug withdrawal, were enrolled in the 73 ergometric laboratories. All patients were followed up after 12 months, at which time electrocardiogram, examination and clinical history were reassessed. Here we report the results of 1111 patients group with the recent myocardial infarction (inferior 3 months). The follow-up was completed in 1031 (93%) patients. RESULTS: The results of exercise testing were normal in 666 (64.6%) patients; angina alone in 33 (3.2%) patients; silent ischemia in 234 (22.7%) patients; symptomatic ischemia in 98 (9.5%) patients. In 270 patients (26.1%) new events occurred: angina (19.7%); myocardial infarction (3.1%; PTCA (4%); CABG (6%); cardiac death (1.4%). The total events were more common in the patients with exercise induced angina (48.5%) and in those who had exercise induced-symptomatic ischemia (48%), in respect of patients with silent ischemia (29.5%) and of those who had normal testing (20.7%) (p = 0.0001). Myocardial infarction rate was higher in patients with symptomatic ischemia (7.1%) that for those of all other groups (silent ischemia: 1.3%, angina: 3%, normal 3.2%) (p = 0.05). Moreover, the patients with symptomatic ischemia had higher incidence of CABG (p = 0.0001). The mortality rate was low among all patients and did not show differences among the groups. Only among the 31 patients (3%) with blood pressure fall was mortality higher that in patients with a normal blood pressure increase. By multivariate logistic analysis the angina induced by exercise maintained its prognostic significance for all the events, but also other variables were significant: poor exercise tolerance and, between clinical variables angina before myocardial infarction. CONCLUSION: The results showed, in patients who underwent to exercise testing after drug withdrawal, a low incidence of cardiac death and of myocardial infarction on 12 month follow-up; the patients with induced-exercise symptomatic schema had a greater risk for all cardiac events, except for death.