Biomedical subjects

Laurence Gabriel

Publications and source records attributed to Laurence Gabriel.

5 recordsLinked to original sources

PubMed2006

Sympathetic control after cardiac resynchronization therapy: responders versus nonresponders.

Cardiac resynchronization therapy (CRT) decreases muscle sympathetic nerve activity (MSNA) in patients with severe congestive heart failure (CHF) and cardiac asynchrony. Whether this affects equally patients who clinically respond or not to CRT is unknown. We tested the hypothesis that the favorable effects of CRT on MSNA disappear on CRT interruption only in those who respond to CRT. Twenty-three consecutive CHF patients participated in the study, among whom 16 presented a symptomatic improvement by one or more New York Heart Association (NYHA) functional classes 15 +/- 5 mo after CRT (responders), and seven had not improved after 12 +/- 4 mo of CRT (nonresponders). MSNA and echocardiographic recordings were obtained in random order during atrio-right ventricular pacing (ARV), without stimulation in patients who were not pacemaker dependent (OFF, n = 17), and during atrio-biventricular pacing (BIV). Responders had a longer 6-min walking distance, a lower NYHA class and brain natriuretic peptide levels, and a better quality of life than did nonresponders (all P < 0.05). MSNA increased by 25 +/- 7% in the responders, whereas it remained unchanged in the nonresponders, when shifting from the BIV mode to a nonsynchronous condition (ARV and OFF modes) (P < 0.01). Cardiac output decreased by 0.7 +/- 0.2 l/min in the responders but did not change when shifting from the BIV mode to the nonsynchronous pacing mode in the nonresponders (P < 0.01). In conclusion, reversible sympathoinhibition is a marker of the clinical response to CRT.

Aged↗

PubMed2006

[The cardiac lung].

Since lungs, great vessels and heart share together the main volume of the thorax, itself limited by the thoracic wall, variations in pressure or volume of each one must influence the work of the others especially in case of disease. Failure of the left heart overloads the pulmonary vascular bed, induces an interstitial oedema followed by an alveolar oedema with mostly restrictive functional consequences on the lung and disturbed gas exchange. Heart failure can be due to systolic or diastolic dysfunction. These consequences of myocardial and valve diseases of the left heart are initially revealed by unusual dyspnea during exercise worsening progressively to symptoms at rest and even during sleep. Informations obtained from history, physical examination, biology, radiography and echocardiography imaging procedures, respiratory function tests and polysomnography help to precise the diagnosis and the prognosis. The treatment of this cardiac lung conditions depends on its precise etiology.

Heart Failure↗

PubMed2005

Prevalence of mechanical dyssynchrony in patients with heart failure and preserved left ventricular function (a report from the Belgian Multicenter Registry on dyssynchrony).

The present study evaluated the prevalence of mechanical inter- and intraventricular dyssynchrony in patients with heart failure and preserved left ventricular (LV) ejection fraction (LVEF). We studied 138 patients with heart failure (age 67+/-11 years; 76% men); 60 patients had preserved LVEF (>40%). Using conventional Doppler echocardiography, an interventricular mechanical delay>or=40 ms was defined as interventricular dyssynchrony. Using pulse-wave tissue Doppler imaging, the time from the beginning of the QRS complex to onset of systolic motion was measured in 4 basal LV segments. A dispersion of >or=60 ms was defined as intraventricular dyssynchrony. The prevalence of inter- and intraventricular dyssynchrony was lower in patients with preserved LVEF than in those with reduced LVEF (17% vs 41%, p<0.01 for interventricular dyssynchrony, 18% vs 36%, p<0.01 for intraventricular dyssynchrony). However, patients with preserved LVEF and a QRS width>or=120 ms had higher values for the parameters for inter- and intraventricular dyssynchrony than patients with a QRS width<120 ms (interventricular mechanical delay 33+/-20 vs 20+/-16 ms, p<0.05; tissue Doppler imaging dispersion 42+/-26 vs 33+/-22 ms, p<0.05). In patients with a QRS width>or=120 ms, the prevalence of inter- and intraventricular dyssynchrony was comparable for patients with preserved and reduced LVEF (42% vs 55%, p=NS for interventricular dyssynchrony and 45% vs 46%, p=NS for intraventricular dyssynchrony). In conclusion, the prevalence of inter- and intraventricular dyssynchrony was low (17% and 18%, respectively) in patients with heart failure and preserved LVEF. However, in the presence of a QRS width of >or=120 ms, this prevalence increased to almost 50%, comparable to that for patients with heart failure and reduced LVEF and a QRS width of >or=120 ms.

Aged↗

PubMed2003

Role of pacing mode and algorithms for effective prevention of atrial fibrillation after coronary artery bypass surgery.

Atrial fibrillation after coronary artery bypass surgery occurs in 30 to 40% of patients. Prophylactic therapy with drugs is not always possible and not always efficient. Atrial pacing may play a role in the prevention of atrial fibrillation. Biatrial pacing with fixed high rate or overdrive and right atrial pacing with overdrive has been demonstrated to reduce the incidence of atrial fibrillation after coronary artery bypass surgery. Avoidance of undersensing and loss of capture with atrial epicardial wires is a technical challenge. Individually tailored and combined approaches are promising future directions for prophylactic therapy.

Algorithms↗

PubMed2003

Myocardial infarction and primary thrombocytosis in a young man.

We report the case of a 27-year-old male smoker with simultaneous myocardial infarction (MI) and acute peripheral ischaemia. At the time of his first hospitalization, the platelet count and the coronary angiogram were normal. Two years later, the patient presented again with a leg artery occlusion, followed, a few days later, by a recurrence of MI. At this time, the platelet count was high and the coronary angiogram revealed an occlusion of the right coronary artery. The diagnosis of primary thrombocytosis was made by bone marrow aspiration and biopsy. Different unusual mechanisms of MI in young people are discussed in this report.

Adult↗