Commotio cordis après impact précordial de Flashball

Less lethal weapons, like Flashball^®, are more and more used since 1995 in law enforcement, even by the local police to neutralize combative individuals and to disperse riot crowds. This gun fires large rubber bullets and has been incriminated many times in cases of face injuries with functional consequences. In this case report, we mention a case of sudden death from cardiac arrest due to low energy chest wall impact of a rubber bullet shot with the Flashball. Commotio cordis is potentialized by a lethal set of three including, a certain impact velocity, an exact location of the hit over the cardiac silhouette, and a precise timing 15 m/s prior to the peak of the T-wave. This case report highlights the fact that such impacts can cause significant injury to internal organs, in particular circonstances, implying the necessity of a raising awareness of the medical staff, in ordre to not underestimate the severity of such injuries.     

Factors correlated with left ventricular mass in hypertensive patients

Left ventricular hypertrophy (LVH) is an independent risk factor in hypertensive patient. THE AIM: Of our study is to evaluate prospectively the relationship between left ventricular mass and clinical, echocardiographical and ambulatory blood pressure data in hypertensive subjects. METHODS: We studied 88 hypertensive patient who underwent clinical and laboratory investigation, echocardiography and 24 hours ambulatory blood pressure monitoring. Correlations were made between these data and left ventricular mass. RESULTS: Clinical data, which correlated well with left ventricular mass, were duration of hypertension, systolic arterial pressure and pulse arterial pressure. In echocardiography left atrial area and left ventricular dysfunction correlated significatively with left ventricular mass. Data from 24 hours blood pressure monitoring as daytime systolic pressure, nighttimes diastolic pressure, ambulatory systolic pressure and ambulatory pulse pressure. CONCLUSION: In hypertensive patient, left ventricular mass correlated well with left atrial dilation and diastolic left ventricular dysfunction. It also correlated with 24 hours ambulatory blood pressure monitoring data.     

Patient selection for biventricular pacing

In heart failure patients with a large QRS width, biventricular pacing has been shown to improve the fonctional status as well as hemodynamic parameters. However, there are non-responders despite of wide QRS complexes (between 15 and 35%). Patients selection might not rely only on electrical parameters. From an electrophysiological concept, clinicians moved toward a more electromechanical analysis, by using non-invasive tools such as Tissue Doppler imaging. Thereby, more than the QRS width, identification of intra-left ventricular asynchrony appears to be a crucial criterion for selecting responders to biventricular pacing. From this fact, several studies have demonstrated the efficacy of biventricular pacing to improve heart failure patients with narrow QRS but with intra-left ventricular asynchrony. Another parameter has been thought to be predominant, i.e. the left ventricular pacing site. If the pacing lead is located within a "slow conduction" area (at this time very difficult to identify during the implant procedure), biventricular pacing will generate a new asynchrony counteracting the beneficial expected. Thus, biventricular pacing appears to be more an electromechanical concept than exclusively electrical for selecting responders. Still, the optimal location of the left ventricular pacing lead remains to be determined.     

Evaluation of ventricular asynchronism by Doppler tissue imaging in patients with idiopathic dilated cardiomyopathy

OBJECTIVES: To study ventricular asynchronism with tissue Doppler imaging in patients with primitive dilated cardiomyopathy and narrow QRS. PATIENTS AND METHODS: We compared a group of patients with DCM and QRS < 120 ms (gr 1, n=25, 52+/-14 yrs, LVEF: 25+/-9%) with a group of normal patients (gr 2, n=16, 36+/-20 yrs). We measured the delays between the beginning of QRS and the beginnings of aortic (QA), mitral (QM), tricuspid (QT) and pulmonary (QP) flows, and of systolic (QSm) and protodiastolic (QEm) wall motion waves recorded with TDI in the basal portion of interventricular septum (IVS) and LV and RV free walls. We then calculated the differences QA-QP, QM-QT, the interparietal differences for QSm and QEm, and the maximal interparietal systolic (QSm max) and diastolic (QEm max) delays. RESULTS: QA, QP, QM and QT were significantly lengthened in group 1 patients but there were no difference between both groups for QA-QP and QM-QT. There was a trend toward a lengthening of QSm and QEm in group 1 patients. Interparietal differences of QSm and QEm were similar in both groups; however, QSm max and QEm max were significantly longer in group 1 patients than in group 2. CONCLUSION: Doppler study of patients with DCM and narrow QRS shows a lengthening of all electromechanical delays and suggests some degree of ventricular asynchronism by showing a significant increase in maximal interparietal systolic and diastolic delays.     

Aortic stenosis with left ventricular dysfunction: evaluation and management

Aortic stenosis is the most frequent valvulopathy in France today. Valve replacement has transformed the prognosis, when indications are present before the appearance of irreversible left ventricular dysfunction. However, some patients are still not seen before this time or their surgery was deferred. Thus, the postoperative prognosis depends on the reversibility of this dysfunction which can occur even when the stenosis is severe and essentially reflects the elevated afterload. The prognosis is less favorable once myocardial fibrosis has developed in response to left ventricular hypertrophy or when ischemic cardiopathy contributes to this dysfunction. The diagnosis and prognosis are based on the confirmation of the presence of a severe stenosis and that the removal of this obstacle will lead to regression of the dysfunction. For this, Doppler echocardiography is determinant, as combined with a dobutamine test, it is able to evaluate the tightness of the stenosis, the severity of the left ventricular dysfunction and its reversibility. When the stenosis is severe with contractile reserve, indicating a better postoperative prognosis, dobutamine does not induce an appreciable change of the aortic area, but the mean pressure gradient, often low prior to dobutamine administration, rises. Although the surgical risk remains higher in the presence of left ventricular dysfunction, the ultimate prognosis is more favorable when the test suggests regression is possible.