Evaluation of the clinical benefit of an electromagnetic navigation system for CT-guided interventional radiology procedures in the thoraco-abdominal region compared with conventional CT guidance (CTNAV II): study protocol for a randomised controlled trial.

BACKGROUND: Interventional radiology includes a range of minimally invasive image-guided diagnostic and therapeutic procedures that have become routine clinical practice. Each procedure involves a percutaneous needle insertion, often guided using computed tomography (CT) because of its availability and usability. However, procedures remain complicated, in particular when an obstacle must be avoided, meaning that an oblique trajectory is required. Navigation systems track the operator's instruments, meaning the position and progression of the instruments are visualised in real time on the patient's images. A novel electromagnetic navigation system for CT-guided interventional procedures (IMACTIS-CT®) has been developed, and a previous clinical trial demonstrated improved needle placement accuracy in navigation-assisted procedures. In the present trial, we are evaluating the clinical benefit of the navigation system during the needle insertion step of CT-guided procedures in the thoraco-abdominal region. METHODS/DESIGN: This study is designed as an open, multicentre, prospective, randomised, controlled interventional clinical trial and is structured as a standard two-arm, parallel-design, individually randomised trial. A maximum of 500 patients will be enrolled. In the experimental arm (navigation system), the procedures are carried out using navigation assistance, and in the active comparator arm (CT), the procedures are carried out with conventional CT guidance. The randomisation is stratified by centre and by the expected difficulty of the procedure. The primary outcome of the trial is a combined criterion to assess the safety (number of serious adverse events), efficacy (number of targets reached) and performance (number of control scans acquired) of navigation-assisted, CT-guided procedures as evaluated by a blinded radiologist and confirmed by an expert committee in case of discordance. The secondary outcomes are (1) the duration of the procedure, (2) the satisfaction of the operator and (3) the irradiation dose delivered, with (4) subgroup analysis according to the expected difficulty of the procedure, as well as an evaluation of (5) the usability of the device. DISCUSSION: This trial addresses the lack of published high-level evidence studies in which navigation-assisted CT-guided interventional procedures are evaluated. This trial is important because it addresses the problems associated with conventional CT guidance and is particularly relevant because the number of interventional radiology procedures carried out in routine clinical practice is increasing. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01896219 . Registered on 5 July 2013.

Does Deep Bradycardia Increase the Risk of Arrhythmias and Syncope in Endurance Athletes?

The aim of this study was to evaluate whether endurance athletes who exhibit deep bradycardia are more prone to arrhythmias and reflex syncope than their non-bradycardic peers. 46 healthy men (ages 19-35) were divided into 3 groups based on whether they were sedentary (SED,<2 h/week) or endurance trained (ET,>6 h/week), and non-bradycardic (NB, resting heart rate (HR)≥60 bpm) or bradycardic (B, resting HR<50 bpm). Resting HR was lower in ETB vs. ETNB and SED (43.8±3.1, 61.3±3.3, 66.1±5.9 bpm, respectively; p<0.001). Thus, 16 SED, 13 ETNB and 17 ETB underwent resting echocardiography, maximal exercise test, tilt test (TT) and 24 h-Holter ECG. Subjects were followed-up during 4.7±1.1 years for training, syncope and cardiac events. Our results showed that incidence of arrhythmias and hypotensive susceptibility did not differ between groups. During follow-up, no episode of syncope or near-syncope was reported. However, cardio-inhibitory syncope occurrence tended to be higher in ETB. Left ventricular end-diastolic diameter index was increased in ETB vs. ETNB and was correlated with resting HR (r=- 0.64; p<0.001). As a result, athletes with deep bradycardia do not present more arrhythmias and more hypotensive susceptibility than their non-bradycardic peers. Cardiac enlargement and autonomic alteration both seem to be involved in an athlete's bradycardia.

Cardiovascular Benefits of Endurance Training in Seniors: 40 is not too Late to Start.

It is unknown whether commencing structured endurance training after 40 years of age is powerful enough to induce beneficial cardiovascular adaptations in later life. 34 men between the ages of 55 and 75 were included: 10 life-long sedentary seniors (SED), 13 endurance master athletes who commenced training≤30 years of age (ET30), and 11 endurance master athletes who commenced training≥40 years of age with no prior physical training (ET40). All performed resting 5-min spectral heart rate (HR) variability analysis, resting and submaximal-exercise echocardiography, and a maximal exercise test. Maximal oxygen uptake was higher and resting HR was lower in both trained groups vs. SED, without difference between ET30 and ET40. Atrial and left ventricle dimensions were greater in ET30 and ET40 vs. SED, without difference between both athletes groups. At rest, total arterial compliance was improved in both ET30 and ET40 compared to SED. During submaximal exercise, improvement in global LV afterload was only observed in ET30 vs. SED. Two powerful markers of health, maximal oxygen uptake and resting HR, did not differ between athletes who commenced training before 30 or after 40 years of age, but were significantly improved compared to their life-long sedentary counterparts.

Ethnic differences in physiological cardiac adaptation to intense physical exercise in highly trained female athletes.

BACKGROUND: Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studies in black male athletes reveal a higher prevalence of electric repolarization and left ventricular hypertrophy than observed in white males; these frequently overlap with those observed in cardiomyopathy and have important implications in the preparticipation cardiac screening era. There are no reports on cardiac adaptation in highly trained black females, who comprise an increasing population of elite competitors. METHODS AND RESULTS: Between 2004 and 2009, 240 nationally ranked black female athletes (mean age 21+/-4.6 years old) underwent 12-lead ECG and 2-dimensional echocardiography. The results were compared with 200 white female athletes of similar age and size participating in similar sports. Black athletes demonstrated greater left ventricular wall thickness (9.2+/-1.2 versus 8.6+/-1.2 mm, P<0.001) and left ventricular mass (187.2+/-42 versus 172.3+/-42 g, P=0.008) than white athletes. Eight black athletes (3%) exhibited a left ventricular wall thickness >11 mm (12 to 13 mm) compared with none of the white athletes. All athletes revealed normal indices of systolic and diastolic function. Black athletes exhibited a higher prevalence of T-wave inversions (14% versus 2%, P<0.001) and ST-segment elevation (11% versus 1%, P<0.001) than white athletes. Deep T-wave inversions (-0.2 mV) were observed only in black athletes and were confined to the anterior leads (V(1) through V(3)). CONCLUSIONS: Systematic physical exercise in black female athletes is associated with greater left ventricular hypertrophy and higher prevalence of repolarization changes than in white female athletes of similar age and size participating in identical sporting disciplines. However, a maximal left ventricular wall thickness >13 mm or deep T-wave inversions in the inferior and lateral leads are rare and warrant further investigation.

Application of multiple correspondence analysis to asses the relation between time after transplantation and sympathetic activity in cardiac transplant recipient.

The aim of the present study was to evidence that the heart reinnervation can occur and it is related with the time after transplantation (evolution with time). Data were evaluated using Multiple Correspondence Analyses (MCA), which is the ideal method to study the relation, probably nonlinear, between the Time After Transplantation (TAT) and the probable restoration of normal heart rate responses of sinus node regulated by the autonomic nervous system. Twenty four nonrejecting transplant recipients (60 +/- 48 months after transplantation) and nine healthy subjects were studied by heart rate variability parameters. Results showed that sympathetic activity is restored some time after transplantation. Until 48 months, the recent HTR are in direct correlation to low values SD and LF and for the oldest transplant recipient, these parameters are similar to that observed in normal subjects.

[Use of the six-minute walk test in cardiology]. / Utilisation du test de marche de 6 minutes en pratique cardiologique.

The symptom-limited exercise test is nowadays the gold standard to assess the exercise tolerance and the effects of different treatments in patients with chronic heart failure (CHF). A simpler alternative to this test is the 6-minute walk test. The 6-minute walk test is easy to realize and well-tolerated. Moreover, it is reliable just after one familiarization practice and requires standardization. Indeed, its conduction, which is submitted to some security precautions, can be altered by variation factors. The distance walked during the 6 minutes was the only parameter studied during the test. This parameter could allow judging the CHF severity and prognostic. The analyse of cardiorespiratory parameters has shown that the 6-minute walk test relative intensity is near to the peak individual values. Moreover, the cardiac and ventilatory adaptation of patient during this test depends to his own functional capacity. Lastly, the 6-minute walk test is a submaximal constant-load exercise, which should be performed in complement to the symptom-limited exercise test in cardiac patients.