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

Efficacy and safety of direct coronary stenting: acute outcome of direct stenting in type A, B, and C lesions

Direct stent implantation is the unique technique of an intracoronary stenting without lesion predilation. It acquired sound acceptance and popularity due to shorter procedural time, fewer contrast dose and reduced incidence of clinically relevant dissections, furthermore, cost effectiveness and less radiation exposure favor this approach. However, the abuse of this technique may result in worse outcome. The objective beyond this study was to assess the safety and feasibility of the direct stenting in different lesion subsets [Type A, B and C]. A prospective non randomized study of 78 patients with total of 84 lesions [29 type A, 41 type B, and 14 type C] underwent direct stenting., Lesions were classified accordingto AHA/ACC task force. TIMI flow before and after procedure, dissectons, perforation, residual diameter stenosis and side branch compromization all were considered. Initial deployment was successful in 80 out of 84 lesions, three lesions successfully stented following predilation. A stent was unable to be deployed in only lesion; however, the lesion was treated with balloon angioplasty alone, all were complex type C lesions and excluded from study. The majority of lesions required only 1 stent [an average of 1.03 stents was used per lesion]. Compared with pre-procedural TIMI flow, post procedure TIMI flow has improved in all lesion subsets, however, it didn't reach a statistical significance except in type B lesions [p=0.007], residual diameter stenosis was significantly higher in type C compared to Type B and A lesions [32.0, 11.62 and 1.67% respectively, p=0.001], side branch compromization observed in 60%, 35.9% and 17.2% in type C, B and A lesions respectively [0.0 15]. Distal dissection observed in 60%, 2.4% and 0% in type C, B and A lesions respectively [p=0.002]. Vessel perforation has complicated primary stenting of type C lesion that successfully treated by prolonged inflation and deployment of another stent, resulting in procedural myocardial infarction. Direct stenting is a safe and effective method for treating coronary artery disease except for complex type C lesions in which complications are warranted

Effect of thrombolytic therapy on QT dispersion in patients with acute myocardial infarction

QT dispersion is an important ECG feature fundamental for initiation of ventricular fibrillation and increased after myocardial infarction. to correlate site of infarction and QT dispersion and assess the effect of thrombolysis on it in patients with acute myocardial infarction [AMI]. The study include 100 patients with AMI were classified into 3 groups: 01: included 30 patients received streptokinase [SK] with successful reperfusion, 02: 30 patients received streptokinase with failed reperfusion and 03: included 40 patients not received SK due to contra-indications. all patients were subjected to resting 12 leads ECG at admission, 2 hours post SK [in G1 and G2] and predischarge. the following parameters were measured [QT interval, QRS interval, JT interval, PR interval, QT dispersion, JT dispersion, QRS dispersion, rate corrected QT, rate corrected JT, QTc dispersion and JTc dispersion]. The study reavles the QTd and JTd values significantly increased in patients < 50 years than pts > 50 years [p < 0.05]; QTd, JTd, QTcd and JTcd were significantly increased with anterior MI than inferior MI [p <0.001]. Among risk factors for coronary artery disease, QTcd and JTcd significantly increased in none obese pts [p < 0.05], QTd, QTcd, JTd, JTcd and QTc significantly increased in diabetics [p < 0.05], while in hypertensives, QTd, QTcd, JTd, JTcd and JTc are significantly increased [p <0.01]. The highest incidence of arrhythmia was in 01 and greater with anterior MI than inferior MI. QTd, JTd, QTcd and JTcd were longer in cases complicating arrhythmia and largest with ventricular fibrillation. In G1, QTd, JTd and QTcd were significantly increased at pre- discharge than at admission [p = 0.001] and than 2 hours after SK [p = 0.001] in G2, QTcd and JTcd significantly decreased 2 hrs after SK [p = 0.05], QTc, JTc, QTcd and JTcd decreased significantly at predischarge than at admission [p < 0.05], in G3, QTc and JTc significantly decreased at pre-discharge than at admission [p 0.001]. Conclusion The study concluded that QT dispersion is increased after myocardial infarction and showed significant rduction with successful thrombolysis. QTd is influenced by hypertension, diabetes mellitus, age and site of myocardial infarction. It could be used equally to QT for analysis