Tweetorial on #vasodilators for low-output #heartfailure
to improve hemodynamics which help to decongest better and allow introduction/uptitration of neurohumorel blockers.
(as addendum to
Vasodilator ⬇️ blood pressure in normal heart through reduction of preload (3/10)
Failing HFrEF = afterload dependent (4/10)
High afterload in failing HFrEF (not HFpEF) is also strongly determined by ⬆️ wall tension (not SVR) as ⬆️ R and ⬇️ wall thickness. SVR is an oversimplification of afterload. (5/10)
Vasodilator ⬆️ cardiac output in failing HFrEF through reduction of afterload often with =/⬆️ blood pressure
(6/10)
Nr 1 vasoactive agent to use in failing HFrEF (cold+wet) = nitroprusside with dose adjustment based upon MAP. Inotropes in this situation = medical error as they induce often "crash and burn scenario" (ie addition of vasopressors - MCS which should NOT have occurred).....(7/10)
See nitroprusside for low-output critical AS (surely afterload is not determined by SVR as AS is fixed resistance, but it's also wall tension) (8/10)
25 patient study in @NEJMpubmed.ncbi.nlm.nih.gov/12724481/
Results of the randomized #ADVOR trial are soon coming your way! It's the largest diuretic trial in acute #heartfailure ever conducted (N=519) and will test acetazolamide on top of loop diuretics. Recruitment is finished and full database lock is anticipated. Find out more (1/9).
There is an underappreciated risk of poor outcome in heart failure patients discharged with ongoing congestion and WRF (2/9).
Pivotal paper of @MarcoMetraahajournals.org/doi/10.1161/ci…
Appropriate and thorough decongestion is class I recommendation in HFA-ESC guidelines so DON'T stop decongestive efforts during WRF (3/9). academic.oup.com/eurheartj/arti…
Door to ‘diuretic’ time: earlier administration of loop diuretics is associated with improved outcomes independent of HF severity (2/9). jacc.org/doi/abs/10.101…
The first dose of the loop diuretic should be 40 mg furosemide (=1 mg bumetanide) in diuretic naïve and twice the home dose in patients on loop diuretic (3/9).
2/10. The kidney is a remarkable vascular organ. Renal blood flow = 1000 ml/min, renal plasma flow = 600 ml/min.
3/10. Elevated central venous pressure affects renal function significantly more than reduced cardiac output in heart failure. jacc.org/doi/10.1016/j.…
Glomerulus: renal blood flow ↓ in HF, but the kidney tries to maintain GFR by afferent arteriolar vasodilation and efferent arteriolar vasoconstriction. This leads to single-nephron hyperfiltration initially preserving total GFR, but further damaging the glomerulus. (2/6)
Proximal tubules: hyperfiltration leads to ↑ water and solutes filtered, but ↓ remaining in the peritubular capillaries. Due to ↑ peritubular capillary oncotic pressure + ↑ renal lymph flow -> ↑ water and Na+ reabsorption in the proximal tubules (3/6)