STARLING’S LAW THE MORE A MYOCARDIAL FIBER IS STRETCHED DURING DIASTOLE, THE MORE IT WILL SHORTEN IN SYSTOLE IT WILL ALSO SHORTEN WITH GREATER FORCE
PRELOAD The length to which a cell is stretched prior. To the next contraction The volume or pressure generated in the ventricles at end-diastole Degree to which a cell is stretched in diastole (preload) force during systole
AFTERLOAD IMPEDANCE OF BLOOD FROM THE VENTRICLE Determined by: The volume and mass of blood ejected from the ventricle The compliance and total cross-sectional area of the vascular space into which the blood is ejected.
Effect of Carvedilol on Left Ventricular Ejection Fraction Patients receiving diuretics, ACE inhibitors, digoxin; follow-up 6 months; placebo (n=84), carvedilol (n=261). Mulitcenter Oral Carvedilol Heart Failure Assessment Adapted from Bristow et al. Circulation. 1996;94:2807-2816. P<.05 vs placebo.
DRYWET WARM COLD CLINICAL ASSESSMENT Warm vs. Cold (Perfusion)- Pulse Pressure Dry vs. Wet (Congestion)- Jugular Venus Pressure
Rapid Assessment of Hemodynamic Status Congestion at Rest Low Perfusion At Rest NO YES Signs/symptoms of Congestion: Orthopnea/ PND JV Distension Hepatomegaly Edema Rates (rare in chronic heart failure) Elevated est. PA systolic Valsalva square wave NO A Warm & Dry B Warm & Wet YES (Low Profile) L Cold & Dry (Complex) C Cold & Wet Possible Evidence of Low Perfusion: Narrow pulse pressure Sleepy/obtunded Low Serum sodium Cool extremities Hypotension with ACE inhibitor Renal Dysfunction (one cause)
Profiles and Therapies of Advanced Heart Failure Congestion at Rest Low Perfusion At Rest NOYES Vasodilators Nitroprusside Nitroglycerine Nesiritied NO Warm & Dry PCW and CI Normal Warm & Wet PCW elevated CI normal YES Cold and Dry PCW low/normal CI decreased Cold & Wet PCW elevated CI decreased NI SVR High SVR Inotropic Drugs Dobuamine Milrinone Calcium Sensitizers
WARM UP THEN DRY OUT DRY WET WARM 1. Diuretics 2. Vasodilators COLD 1. Vasodilators 2. Positive Inotropics 1. Positive Inotropics 2. Vasodilators 3. Diuretics
NEWER THERAPEUTICS I. Biventricular Pacing I. EECP I. Measurement of BNP levels