Single chamber pacemakers versus dual chamber pacemakers the effect on cardiac physiology

The aim of this study was assessment of cardiac functions and quality of life in DDD versus VVI pacing modes. Thirty patients had DDD pacing with a primary diagnosis of acquired symptomatic bradycardia were reprogrammed to VVI mode for four weeks. They were followed by transthoracic echocardiographic examination during DDD pacing mode and restudied after reprogramming to VVI pacing mode. Parameters observed were chamber dimensions [MM], chamber volumes, systolic functions, cardiac output [Simpson's method],Colored jet area method to assess Mitral regurgitation [MR] and Tricuspid regurgitation [TR] and Estimated Systolic Pulmonary Artery Pressure [ESPAP]. Thirty patients were mean age [47.9 +/- 13.2], 10 males and 20 females, Three patients only were hypertensive [10%]. There were significant decrease of the following parameters including LV systolic function [EF% [P value=0.002], CO [P value=0.008]] Left ventricular end diastolic diameter [P value=0.03] and Left ventricular end diastolic volume [P value=0.04] in VVI mode. There were significant increase in Right ventricular end diastolic diameter: [P value=0.004], the incidence and degree of TR [P value=0.03] in VVI mode. There were no statistically significant difference between both modes as regard; Left ventricular end systolic diameter and volume. Left atrial dimension, Incidence and degree of MR and Estimated Systolic Pulmonary artery Pressure. From the present study we concluded that; Cardiac functions and quality of life are better in DDD mode compared to VVI mode

Comparative study between echocardiography and MRI in the diagnosis of rheumatic valvular heart diseases

Rheumatic heart disease is a very common cause of cardiovascular mortality and morbidity Doppler echocardiography has emerged as the primary way for assessing of valvular heart disease; either function or structure, myocardial dysfunction, and pulmonary hypertension. Recent reports have demonstrated that dynamic magnetic resonance imaging [MRI] may serve as an attractive, alternative or complement to echocardiography, This non-invasive technique provides three dimensional anatomic and functional data and a potentially more accurate measurement of ventricular function than is possible with echocardiography. The present study compares between echocardiography and MRI as diagnostic procedure for the diagnosis of rheumatic heart disease and its complications. Twenty four patients complaining of rheumatic heart diseases where diagnosed at Sayed Galal hospital during the period from May 2007 to April 2008 with ages ranging from 15 to 35 years undergo, history tacking, full clinical examination, ECG, echocardiography using Esaote XP-10 Biomedical corporation equipped with 2.5-5 transducer and CGE MRI Magnetom symphony 1.5 tesla[Siemens Medical system Erlangen Germany] at Mustafa Mahmoud Hospital and some private centers. Our study showed positive correlation between CMR and Echo as regard left ventricular volumes and function, mitral and aortic valve areas, pressure gradient across mitral valve, also positive correlation between [VEC] MRI and ECHO. regarding the severity of mitral and aortic regurgitation but no significant correlation were detected between [CGE] MRI and Echo regarding severity of mitral and aortic regurgitation. CMR is sensitive and specific method compared to Echo as regard estimation of left ventricular volume and function, mitral valve area, diastolic pressure gradient across mitral valve, aortic valve area and systolic pressure gradient across aortic valve, [VEC] MRI is more sensitive and specific than [CGE] MRI as regard measurement of severity of mitral and aortic regurgitation. We chose MRI rather than cardiac catheterization as a reference standard to avoid the invasive maneuver and radiation exposure of cardiac catheterization