High Tension on the High Seas Primary HTN & Hypertensive Crisis

3.2 – “High Te Tension nsion on the High Seas”: Primary HTN & Hypert Hypertensive ensive crisis • Antihypertensives (high pressure pipes) Primary (es (essential) sential) HTN (primar (primaryy deck) • No uniform agreement on best first line treatments for essential HTN. Regimen should be tailored to other co-morbidities. • Overall, all drugs have similar efficacy for ↓BP, but high variability between patients. Goal is to find best regimen that causes fewest adverse effects. o Elderly patients often respond better to CCB, specifically long acting dihydropyridines (older patient in dipping pool). o ACE-I/ARBs first line treatment for HTN in patients with HF, MI, or diabetes (balloon, broken strings on banjo, candy) • Monotherapy unlikely to work if BP > 20/10 mmHg above goal at initiation. Start with two (2 recommended if >20 # sign) • First line drugs: thiazides, ACE-inhibitors/ARBs, long-acting CCBs (white-thighed diver, card dealers, soft serve machines). Note that of the thiazides chlorthalidone has better evidence of ↓CV events. HTN emerg emergency ency (sinking shi ship) p) • HTN emergency is defined as SBP > 180 or DBP > 120, or signs of end organ damage (respectively: the protractor & rule in the boiler room; hole in the hull heralds the end). • Don’t want to lower BP too quickly or too much. Goal is 10-20% decrease over first hour, 5-15% more over next 23 h. • Vasodilation is a common effect of many treatments (big red smokestack). Produce ↓SVR which can lead to hypotension and reflex tachycardia (doctor with reflex hammer), ↑renin & reflexive SNS activation (doctor with renin umbrella). ↓afterload (weight on loaded scale getting reduced) • β-1 antagonists (e.g. esmolol, metoprolol) (muted β buglers) o given IV by directly ↓HR & contractility. o Laβlol (α & β effects) may also be effective by directly ↓HR & contractility + vasodilation. • Dihydropyridine CCBs (clevidipine, nicardipine) (clover on a nice card) o IV administration o Vasodilation (arteriolar) (dilated sleeves) • Hydralazine (hydro boat) o Direct arteriolar vasodilator with little effect on venous dilation (direct hose to hydrant) o Primarily limited to pregnant women (pregnant woman) o Can cause hypotension (woman fainting). Can be sudden, within 30 min. o Reflex tachycardia (doctor with reflex hammer approaching woman) Often coadministered with β blocker to blunt this response (bugler stopping doctor). ▪ May worsen angina (anginal anvil). ▪ Contraindicated with angina or known coronary artery disease. o Can be useful for managing HTN with SHF. Combined with nitrates provides mortality benefit & systematic relief in LV-SHF (d/t afterload + preload reduction respectively) (dynamite + HF balloon; angel flag for mortality benefit) o Can rarely cause drug-induced lupus (wolf in the bow) • Nitroprusside (nitro-pressure speedboat) o Causes systemic vasodilation d/t NO. Promotes smooth muscle relaxation by ↑cGMP (grump in the water). o Unlike most nitrates, which only dilate veins that return to the heart to reduce preload, nitroprusside causes arteriolar & venous dilation (lady has dilated sleeves o Metabolized to cyanide (blue smoke). May cause cyanide poising especially in long-term use or with renal failure • Fenoldopam (old lady Pam) o D1 receptor agonist with no effect on α or β receptors (single dope rope) o Stimulates cAMP (tent). Results in vasodilation (dilated sleeves), especially renal, mesenteric, coronary (crown). ▪ Only agent that improves renal perfusion while ↓overall BP (renal flotation device) o Causes natriuresis (spilling peanuts)