Cardiogenic shock

Systemic hypoperfusion:

–      cardiac index [<2.2 (L/min)/m²]

–      sustained systolic arterial hypotension (<90 mmHg),

–      elevated filling pressure [pulmonary capillary wedge pressure (PCWP) > 18 mmHg].

    

It is associated with in-hospital mortality rates >50%

•       Major causes 

–      Acute myocardial infarction (MI): most common

•       Most often due to massive MI (5-10%)

–      dead myocardium does not contract

–      40% loss of muscle mass or greater

–      Cardiomyopathy or myocarditis or cardiac tamponade: less frequent

昨天看到的病人是hereditary and preipartum-

associated DCM 造成的heart 

failure 兩側下肢水腫 端坐呼吸 今天作心導管和心臟切片 準備換心

•       Leading cause of death of patients hospitalized with MI.

•       Early reperfusion therapy for acute MI decreases the incidence of CS.

•       The rate of CS complicating acute MI fell from 20% in the 1960s but has plateaued at ~8% for >20 years.

•       Shock is typically associated with ST elevation MI (STEMI) and is less common with non-ST elevation MI

•       LV failure accounts for ~80% of the cases of CS complicating acute MI.

•       Acute severe mitral regurgitation (MR), ventricular septal rupture (VSR), predominant right ventricular (RV) failure, and free wall rupture or tamponade account for the remainder.

•       Shock is present on admission in only ¼ of patients who develop CS complicating MI; ¼ develop it rapidly thereafter, within 6 h of MI onset. Another ¼ develop shock later on the first day.

•       Subsequent onset of CS may be due to reinfarction, marked infarct expansion, or a mechanical complication.

•       Initial damage/event

•       Cascade of inflammatory and other mediators- histamine, LTs, PAF, lactic acid, myocardial depressant factor

•       Increased oxygen demand, worsened coronary perfusion

•       Damage begets more damage

•        

•        

•        

Presentation•       Acute MI typical presentation

Tachycardia, cool clammy skin, hypotension, poor peripheral pulses, decreased urine output, MS changes

•       Jugular vein distension, pulmonary congestion

•       Rule out surgically corrected causes-

–      valves, papillary rupture, tamponade

•       Lab studies specific for underlying cause

–      cardiac enzyme, Complete blood count (CBC), electrolytes, coagulation factors, arterial blood gas, etc..

–      X-ray, echocardiography, Electrocardiography, etc

•       ABCs: airway, breathing,circulation

–      Oxygen

–      Ventilation

–      Vasopressors (volume expansion?)

•       Central line placement

•       Address cause

–      revascularization, PCI (percutaneous coronary intervention), stent, thrombolytics

•       Nitrates, morphine

–      reduce pain

–      hypotension dangerous

•       Dopamine, dobutamine

•       Amrinone, milrinone

•       Beta blockers when able

–      BP, HR limitations

•       Misc: diuretics, antiplatelet, LMWHs (low molecular weight heparin), etc

Outcome

•       Very very poor

–      70% with medical management

–      perhaps 30-50% with surgical/cath lab intervention

•       Prevention

•       Early identification