Transcript After load
Aortic stenosis Heart failure Dr.Aso faeq salih a narrowing of the valve that opens to allow blood to flow from the left ventricle into the aorta and then to the body. Valvular, subvalvular or supravulvalar – 5% Failure of : ◦ development of the three leaflets ◦ Resorption of tissue around the valve Depend on degree of stenosis Mild to moderate : asymptomatic Severe: ◦ easy fatigability, exertional chest pain, syncope ◦ In infant with severe stenosis can survive only if: PDA permits flow to the aorta and coronary arteries • Physical sign: – Small volume, slow rising pulse – Sys ejection murmur at Rt 2nd IS and radiating to neck – ejection click – Thrill at RUS border/suprasternal notch/carotid • Cong bicuspid aortic valve: – Prone to calcific degeneration in middle age – Increased risk of infective endocarditis (a) Aortic stenosis. (b) Murmur. (c) Chest X-ray. (d) ECG. Ballon valvulopasty ◦ Symptoms on exercise/ high resting pressure gradient(>64mmHg) ◦ High risk of significant valvular insufficiency Surgical mx ◦ When BV unsuccesful or significant valvular insufficiency develops Subacute bacterial endocarditis prophylaxis Salt &water retention by kidney increase pre load . Vasoconstriction , through Renin / Angiotensin increase after load . Increased circulating Catecholamine increase C.O . Increase R.R to promote excretion of Co2 . Increase renal excretion of H- ion & retention of HCO3 to maintain a normal PH . The Pre primary determinants of SV : load (volume work ). After load ( pressure work ) . Contractility (intrinsic myocardial function ) Cardiac rhythm disorders may be caused by the following: Complete heart block , Supraventricular tachycardia , Ventricular tachycardia , Sinus node dysfunction Volume overload may be caused by the following: 1.Structural heart disease (eg, ventricular septal defect,[3] patent ductus arteriosus, aortic or mitral valve regurgitation, complex cardiac lesions) 2.Anemia 3.Sepsis Pressure overload may be caused by the following: Structural heart disease (eg, aortic or pulmonary stenosis, aortic coarctation) Hypertension Systolic ventricular dysfunction or failure may be caused by the following: Myocarditis , Dilated cardiomyopathy Malnutrition , Ischemia Diastolic ventricular dysfunction or failure may be caused by the following: Hypertrophic cardiomyopathy , Restrictive cardiomyopathy , Pericarditis , Cardiac tamponade (pericardial effusion) Depends on the degree of cardiac reserve . Infants Feeding : difficulties & sweating . Poor weight gain . Irritability & weak cry . Respiratory distress . Fatigue . Effort intolerance . Anorexia , abdominal pain . Dyspnea . Cough . Orthopnea . • • • • • • • • Respiratory distress . Increased JVP . Hepatomegally . Edema . Basal crepitation . Cardiomegaly . Gallop rhythm . Holosystolic murmur of mitral , tricuspid insufficiency . cardiac enlargement , pul. vascularity. ECG : chamber hypertrophy , ischemic changes , rhythm disorders . Echo : assess ventricular function . Doppler ; calculate C . O . Arterial O2 : may be decreased ( pul. Edema ) . Blood gas analysis : metabolic & respiratory acidosis . Electrolyte disturbances : hypo Na , hypo glycemia . CXR Underlying cause must be removed or alleviated if possible . General measures : Adequate sleep & rest . Position : older children semi upright position infants infant chair . Modification of activities . Diet : increase no. of calories / feeding up to 24 cal/oz, or supplementing breast feeding . Low Na formula is not recommended . Older children : diet with (no added salt ) & abstinence from food containing high concentration of salts . Respiratory distress : Semi upright position . Continuous O2 , +ve pressure ventilation . _ ve inotropic factors should be corrected : hypoglycemia , hypo Ca , acidosis . Sedation for irritability & excessive crying . Treatment of associating pul. Infection . Temperature control . Medications Diuretics used in treating HF : . Inotropic agents . After load reducing agents .