Exercise Tolerance and Post Exercise Diastolic Filling Pattern in patients with resting Grade I Diastolic Dysfunction

INTRODUCTION: Diastolic dysfunction is one of the commonly seen abnormalities in heart disease patients. It is commonly associated with diabetes, hypertension, LV hypertrophy, increasing age and coronary artery disease. These type of abnormalities are seen even in patients with normal systolic function. Patients having normal LV systolic function increase their cardiac output during exercise by increasing their stroke volume and heart rate. Initially stroke volume increases and later increase in heart rate is responsible for additional increase in cardiac output. AIMS AND OBJECTIVES: 1. To assess the functional capacity/exercise tolerance of patients with resting Grade I DD. 2. To identify different patterns of Doppler parameters before and after exercise in patients with resting Grade I DD. 3. To assess the association between LV filling pattern post exercise and functional capacity/exercise tolerance in patients with resting Grade I DD. 4. To identity the subgroup of patients with grade I DD who show increase in LV filling pressures after exercise. METHODOLOGY: Sample size: 212 consecutive patients visiting the outpatient section of the cardiology department were screened, of which 108 patients were excluded from the study. The remaining 104 patients were recruited for the study after applying the inclusion criteria. Setting: Outpatient sections of the Department of Cardiology, Madras Medical College and Rajiv Gandhi Government General Hospital, Chennai – 3. Study design: Single Centre, Case control analytical study. Period of the study: The study was done between January 2012 to December 2012. Inclusion criteria: Group I: Subjects with resting grade I DD (E/A ratio less than 1and DT less than 240 msec) in sinus rhythm with normal resting wall motion and ejection fraction more than 55%. Group II: Subjects with normal resting diastolic function (E/A ration > 1) in sinus rhythm with normal resting wall motion and ejection fraction more than 55%. Exclusion Criteria: • Age less than 30 years and more than 60 years, • Valvular regurgitant lesions of moderate and severe grades, • Coronary artery disease, • Chronic diseases like chronic kidney disease, chronic liver and lung diseases, • Pregnancy, • Subjects with arrhythmias, • Subjects with systolic dysfunction (EF < 55%), • Uncontrolled Hypertension (SBP >200 mm Hg, DBP > 110 mm Hg), • Acute systemic illnesses like pulmonary embolism, aortic dissection, • Subjects with inability to perform treadmill test. CONCLUSION: 1. The functional capacity/ exercise tolerance among subjects with grade I diastolic dysfunction at rest showed a heterogenous pattern. 2. The post exercise transmitral Doppler changes among subjects with grade I diastolic dysfunction at rest showed divergent patterns which can aid in evaluating degree of diastolic dysfunction. 3. There is a clear correlation between the functional capacity/exercise tolerance with post exercise transmitral Doppler changes in both groups 4. The appearance of E/A reversal post exercise in people with previous normal transmitral patterns also have exercise intolerance. 5. Transmitral Doppler pattern at rest and post exercise gives further thoughts about impaired relaxation of left ventricle