Two-beam deckhouse theory including shear deflection.

http://archive.org/details/twobeamdeckhouse00kin

Comparison of right ventricular outflow tract pacing with apical placement using haemodynamic parameters

Some studies have demonstrated that synergistic activation of the two ventricles is also necessary besides atrioventricular synchronisation for the maintenance of cardiac function at an optimum level. In this study, it has been investigated whether the effects of implantation of a pacemaker electrode in the right ventricular outflow tract (RVOT) instead of the classical right ventricular apical (RVA) position can preserve better left ventricular function or not. For this purpose, a temporary pacemaker electrode was placed firstly into the RVOT and pacing was performed at 10 beats/minute more than the intrinsic heart rate in 17 patients (8 men and 9 women, mean age 53.23 ± 10.11). Cardiac output (CO) and cardiac index (CI) were measured by the thermodilution method. Secondly, the electrode was placed in the RVA for similar pacing and CO and CI measurements were made in the same manner. CO and CI measurements from RVOT pacing were significantly higher than RVA pacing (5.57 ± 1.9 litres/min and 4.95 ± 1.77 litres/min, p < 0.02; 3.16 ± 0.85 litres/min/m2 and 2.82 ± 0.82 litres/min/m2, p < 0.01 respectively). In women and patients with coronary artery disease RVOT pacing was found to provide better haemodynamic parameters than the RVA pacing. In conclusion, the data obtained suggests that implantation of a ventricular pacemaker electrode into RVOT instead of RVA may provide better cardiac performance

Chylous ascites due to constrictive pericarditis

Chylous ascites due to constrictive pericarditis is an extremely rare clinical entity, possibly caused by the augmented lymph production and high impedance to lymph drainage due to central venous hypertension. The authors describe a patient with chylous ascites caused by constrictive pericarditis in the absence of lymphatic obstruction. Cardiac catheterization is essential for the confirmation of accurate diagnosis of constrictive pericarditis. Magnetic resonance imaging of the heart is also very helpful in the diagnosis. The patient was symptom free and his ascites and edema completely resolved after pericardiectomy

Effect of left and right lateral decubitus positions on mitral flow pattern by Doppler echocardiography in patients with systolic or diastolic dysfunction

Doppler echocardiographic asessment of the mitral valve provides a considerable amount of information regarding the diastolic filling characteristics of the left ventricle. Patients with congestive heart failure usually complain of increasing dyspnea in left lateral decubitis (LLD) position, compared with the right lateral decubitus (RLD) position which is called trepopnea. In this study, the effects of LLD and RLD positions on mitral flow velocities in patients with systolic or diastolic dysfunction were examined. Sixteen patients with systolic dysfunction (Group I), 16 patients with diastolic dysfunction (Group 2), and 16 normal subjects (control group) constituted the study group. Peak early diastolic (E) and atrial (A) flow velocities, EIA ratios, deceleration time (DT), flow duration (PD), the velocity time integral of mitral total flow during diastole (VTI), transmitral mean gradient during diastole (MGR) were calculated in each decubitis position. In group I; DT was shorter, VTI and FD were significantly lower and E/A ratio was significantly higher than normal control subjects in LLD position. In group I, RLD position resulted in an increase in DT (124.81 +/- 21.6, 155.6 +/- 23,p = 0.004), increase in VTI (0.13 +/- 0.03, 0.16 +/- 0.09, p = 0.02) and a decrease in E/A ratio (1.92 +/- 1, 1.62 +/- 0.88, p = 0.006) suggesting a decrease in left ventricular preload on changing position. On the other hand, no significant change on mitral flow pattern was detected after turning over the RLD position in patients with diastolic dysfunction. There was also no significant mitral flow change in the control group on RLD position. The results of this study suggest that the Doppler derived mitral flow pattern is significantly altered by a postural change from the LLD to RLD positions in patients with systolic dysfunction. This may help to explain the trepopnea in these patients

Does impaired left ventricular relaxation affect P wave dispersion in patients with hypertension?

Objective: P wave dispersion (PD) is considered to reflect the heterogeneous conduction in atria. We investigated whether there was a correlation between the left ventricular (LV) relaxation and PD