Significant mitral regurgitation is protective against left atrial spontaneous echo contrast and thrombus as assessed by transesophageal echocardiography.

This retrospective study examines whether a relationship exists between the severity of mitral regurgitation (MR) and the presence of left atrial spontaneous echo contrast and/or thrombus (SEC/THR) as assessed by transesophageal echocardiography in 427 consecutive patients. Clinical data were evaluated in 316 of these patients. Nine percent of patients with MR < or = 2+ versus < 1% of those with MR > or = 3+ had SEC/THR (p < 0.03). Atrial fibrillation, left ventricular dysfunction, mitral stenosis, and mitral valve prosthesis were demonstrated to be independent positive predictors of left atrial SEC/THR, whereas MR > or = 3+ was an independent negative predictor of SEC/THR. SEC/THR was less common in patients with MR > or = 3+ than in patients with MR < or = 2+ for any given number of independent positive predictors of SEC/THR. This relationship did not hold true in patients with a mechanical mitral prosthetic valve. Clinical data revealed a trend towards a lower prevalence of stroke or transient ischemic attacks in patients with MR > or = 3+. Stroke and transient ischemic attacks were significantly more common in patients with SEC/THR (p < 0.001). We suggest that significant MR may be protective against the formation of left atrial SEC/THR.

Patent foramen ovale: a nonfunctional embryological remnant or a potential cause of significant pathology?

A patent foramen ovale (PFO) is an embryological remnant found in 27% of adults. It is a potential right-to-left intracardiac shunt. Shunting may be the result of reversal in the interatrial pressure gradient or abnormal streaming of blood in the right atrium. The pathologic consequences of right-to-left shunting include hypoxemia and paradoxical embolism. PFO may exacerbate preexisting hypoxemia or be its primary cause. Paradoxical embolism through a PFO is well documented. Its role in cryptogenic stroke remains controversial. A PFO may be detected by both invasive and noninvasive techniques. Contrast transesophageal echocardiography with provocative maneuvers is the diagnostic method of choice allowing visualization of the shunt. Patients with cryptogenic stroke should be screened for a PFO. If detected, noninvasive studies for deep vein thrombosis are recommended. Treatment must be tailored to the presentation. Surgical or transcatheter closure is recommended for hypoxemia. Prevention of venous embolism (air or thrombus) with or without closure of the PFO is recommended for paradoxical embolism.