Calculation of Mitral Valve Area in Mitral Stenosis: Comparison of Continuity Equation and Pressure Half Time With Two-Dimensional Planimetry in Patients With and Without Associated Aortic or Mitral Regurgitation or Atrial Fibrillation.

Accurate measurement of Mitral Valve Area (MVA) is essential to determining the Mitral Stenosis (MS) severity and to achieving the best management strategies for this disease. The goal of the present study is to compare mitral valve area (MVA) measurement by Continuity Equation (CE) and Pressure Half-Time (PHT) methods with that of 2D-Planimetry (PL) in patients with moderate to severe mitral stenosis (MS). This comparison also was performed in subgroups of patients with significant Aortic Insufficiency (AI), Mitral Regurgitation (MR) and Atrial Fibrillation (AF). We studied 70 patients with moderate to severe MS who were referred to echocardiography clinic. MVA was determined by PL, CE and PHT methods. The agreement and correlations between MVA's obtained from various methods were determined by kappa index, Bland-Altman analysis, and linear regression analysis. The mean values for MVA calculated by CE was 0.81 cm (±0.27) and showed good correlation with those calculated by PL (0.95 cm, ±0.26 ) in whole population (r=0.771, P<0.001) and MR subgroup (r=0.763, P<0.001) and normal sinus rhythm and normal valve subgroups (r=0.858, P<0.001 and r=0.867, P<0.001, respectively). But CE methods didn't show any correlation in AF and AI subgroups. MVA measured by PHT had a good correlation with that measured by PL in whole population (r=0.770, P<0.001) and also in NSR (r=0.814, P<0.001) and normal valve subgroup (r=0.781, P<0.001). Subgroup with significant AI and those with significant MR showed moderate correlation (r=0.625, P=0.017 and r=0.595, P=0.041, respectively). Bland Altman Analysis showed that CE would estimate MVA smaller in comparison with PL in the whole population and all subgroups and PHT would estimate MVA larger in comparison with PL in the whole population and all subgroups. The mean bias for CE and PHT are 0.14 cm and -0.06 cm respectively. In patients with moderate to severe mitral stenosis, in the absence of concomitant AF, AI or MR, the accuracy of CE or PHT method in measuring MVA is nearly equal. But in the presence of significant AI or MR, PHT method is obviously superior to CE and in the presence of AF neither have sufficient accuracy.

Prevalence and distribution patterns of Sarcocystis in camels (Camelus dromedarius) in Yazd province, Iran.

Sarcocystis spp., are zoonotic cyst-forming coccidian parasites that cause sarcocystosis. This study was conducted to investigate the prevalence as well as distribution patterns of Sarcocystis spp. infection in slaughtered one-humped camels of Yazd province, Iran. Muscles of 130 camels were investigated for either macroscopic or microscopic sarcocysts during summer 2009. No macroscopic cyst was observed in the animals at naked eye inspection. Of examined camels, 67 (51.5 %) were positive for bradyzoites of the parasite by pepsin-digestion method. The infection rates of infected animals were 55.22, 50.75, 38.81, 34.33, and 28.36 %, in esophagus, heart, masseter muscle, intercostal muscle and limb muscle, respectively. Esophagus was the most commonly infected organ. No significant difference in the rate of infection between male (52.08 %) and female (51.22 %) camels was observed. Logistic regression analyses showed that infection rates' risk increased with increment in age of camels. This considerable prevalence of microscopic Sarcocystis spp. in Yazd province camels reflects a significant role played by wild and domestic carnivores in the transmission of these parasites.