Cardio OB Flashcards
Mitral stenosis
Cause: rheumatic
Pathophys: LA dilation, pulmonary HTN, atrial fib (from the dilation)
in Pregnancy: heart failure from fluid overload, tachycardia. Goal is to keep them DRY
Mitral insufficiency
Cause: rheumatic, MVP, LV dilation
Pathophy: LV dilation, eccentric hypertrophy
Pregnancy: increased ventricular function with after load decrease. Gets better in pregnancy!
(Schnider, Anesthesia for OB, p.459) - 2nd most common valvular defect in pregnancy. LV volume work is chronically increased. Usually well tolerated. Most tolerate pregnancy well, have sx later in life. Decreased PVR improves forward flow. However increased SVR due to pain, bleeding, etc can cause LV failure. Want LV afterload reduction. Not a big problem with decreased preload
aortic stenosis
Congenital biscuspid
causes LV concentric hypertrophy, decreased cardiac output
In pregnancy: moderate stenosis is tolerated, severe if life threatening with decreased preload (due to hemorrhage or regional anesthesia)
Aortic insufficiency
Rehaumtic, CT disorder, congenital
Causes Lv hypertrophy and dilation,
Ventricular function improved in pregnancy with after load reduction
Pulmonary stenosis
Congenital, rheumatic
Severe stenosis associated with RA and RV enlargement
Mild stenosis is tolerated, severe stenosis associated with R heart failure and atrial arrhythmias
Pulmonary hypertension
Eisenmeger cause
Greatest risk when there is diminished venous return and right ventricular filling (decreased preload) from hemorrhage or regional anesthesia
Swan values prepregnancy vs. pregnancy:
a) decr SVR, decr PVR, incr PCWP
b) decr SVR, decr PVR, no change PCWP
A
What decreases in pregnancy (hemodynamic parameters) and what increases
Decreases: SVR, PVR (pulmonary vascular resistance), colloid oncotic pressure
Increases: CO, Wedge, HR, MAP. LVSW (left ventricular stroke work)
Normal values in pregnancy on page 1171 C&R.
Pulmonary artery systolic: 15-25,
Pulmonary artery diastolic: 8-15
Systemic Vascular Resistance (SVR): 1210 (dyne x cm x sec)
CO: 6.2 (L/Min)
Pulmonary capillary Wedge Pressure: 7.5 (mm Hg )
HR 83 (beats/min)
Pulm Vasc Resistance: 78 (dyne x cm x sec)
Colloid oncotic pressure: 18 (mm Hg)
Left ventricular stroke work (LVSW): 48 (g x m m2)
Central venous pressure 3.6 (mm Hg)
SVR = ((MAP-RAP))/CO x 80
Elevated pulmonary artery pressures and slightly decreased CO, low PCWP
PE
Pulmonary catheter with the following readings is consistent with which process?
PAP - 42/22: normal systolic = 20-30, normal diastolic = 8-12 HIGH
SVR – 1200 normal = 1200
CO - 4.3 normal at term = 6, so this is LOW
Wedge - 7.0 normal at term = 7.5, so slightly low
RAP – 13
a. Sepsis
b. PE
c. Anaphylaxis
d. PIH
e. Cardiac tamponade
PE
PE = elevated RA and RV pressure, elevated SVR, low PCWP, and low CO.
Decreased SVR, increased CO:
Shock
Elevated SVR, Low Wedge pressure, elevated LVSW
HTN
Pulmonary edema PCWP
PCWP>20
IHSS
(Critical Care OB, Belfort et al, p273) – Although the increased blood volume of normal pregnancy helps LV filling and performance, the positive effect of pregnancy is counterbalanced by a fall in SVR and an increase in HR resulting in reduced LV diastolic filling time and myocardial contractility. Key to avoid hypotension and tachycardia.
IHSS
(Critical Care OB, Belfort et al, p273) – Although the increased blood volume of normal pregnancy helps LV filling and performance, the positive effect of pregnancy is counterbalanced by a fall in SVR and an increase in HR resulting in reduced LV diastolic filling time and myocardial contractility. Key to avoid hypotension and tachycardia.
