Hemodynamics Goals for Valvular Heart Disease

General Approach to Perioperative Cardiac Optimization

RATE

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RHYTHM

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PRELOAD

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AFTERLOAD

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CONTRACTILITY

Case 1

• A 72 year old man is presenting for hemicolectomy for colon cancer. Comorbidities include DMII, HTN, HLD, prior CVA without residual neurologic deficits, and aortic stenosis. He can climb 2 flights of stairs without pausing and walks 3 miles/day for exercise. His cardiologist has been following his aortic stenosis with serial echocardiograms. His most recent TTE report reads:

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• “Dilated left atrium, LVH with grade II diastolic dysfunction, EF 55-60%, normal RV function. The aortic valve is trileaflet and calcified but opens normally during systole. AVA by continuity equation is 0.8 cm². Mean gradient 28 mmHg. Max velocity is 3 m/s. Trace MR. Trace PR. Trace TR.”

Aortic Stenosis

Aortic Stenosis

• Chronically high afterload
• Increased systolic wall tension
• Parallel replication of sarcomeres = concentric LVH
• Diastolic dysfunction

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• “End-stage” = LV failure, reduced ejection fraction

How would you manage this patient?

• RATE
• Avoid tachycardia or extreme bradycardia
• Tachy = decrease diastolic filling time, increased O₂ consumption = risk of myocardial ischemia, low output
• May need anti-anxiety premedication
• RHYTHM
• Need atrial kick for filling of LV = ensure sinus rhythm
• Consider defibrillator pads
• PRELOAD
• Increase LVEDV to counteract diastolic dysfunction
• May need gentle fluid bolus
• AFTERLOAD
• Keep high to ensure adequate perfusion of a hypertrophied LV
• CONTRACTILITY
• If low EF, may need inotropy

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Case 2

• A 43 year old female with a history of IVDU presents for urgent decompression of a spinal epidural abscess in the setting of progressive lower extremity weakness. She denies comorbidities, though she was hospitalized 1 year ago with Staphylococcal bacteremia. During that hospitalization, she had a TEE which showed:
• “Normal right and left atrial diameters. The left ventricle is mildly dilation with an LVEF of 65-75; no wall motion abnormalities. Diastolic function is normal. RV function is normal. Mild MR. Mild TR. The aortic valve is trileaflet without significant calcification but poor coaptation of leaflets. There is moderate aortic insufficiency with a measured vena contracta of 5 mm. Regurgitant pressure half-time is 400 ms. The ascending aorta measures 3.4 cm in maximum diameter. Visualized segments of the aortic arch appear normal. There is no reversal of diastolic flow in the descending thoracic aorta. No evidence of endocarditis on visualized portions of the valves.”

Aortic Regurgitation

Aortic Regurgitation

• Chronic high preload leads to increased wall tension and eventual
• In-series replication of sarcomeres = eccentric LVH

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• “End-stage” = low cardiac output/ejection fraction due to chronically increased wall tension and low coronary perfusion pressure
• Leads to need for increased sympathetic tone of peripheral vessel beds = worsens AR
• If acute, LV has not had time to remodel and is prone to failure

How would you manage this patient?

• RATE
• AVOID bradycardia. Prefer tachycardia.
• Brady = increased diastolic filling time, low coronary perfusion pressure = risk of myocardial ischemia
• Tachy = increase HR in setting of already large LVEDV = allows for appropriate cardiac output
• RHYTHM
• Sinus preferable, though most important to have rapid ventricular systole
• PRELOAD
• Usually not an issue, as LVEDV is high due to regurgitant flow
• AFTERLOAD
• Keep low to reduce regurgitation
• CONTRACTILITY
• If acute AR, may need intropy (e.g. dobutamine or milrinone preferred)

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Case 3

• A 62 year old female is presenting for diagnostic hysteroscopy for vaginal bleeding. Her comorbidities include HTN for which she is on 4 medications, atrial fibrillation on warfarin, HLD, DMII, current cigarette use, GERD, obesity, a chronic non-productive cough, and progressive anemia which required a blood transfusion 3 months ago. She leads a sedentary lifestyle and takes the elevator to her 3^rd floor apartment. A pharmacologic stress test 4 months ago did not reveal EKG or TTE changes consistent with ischemia but did report an LVEF of 45% at rest, a dilated RV with probably normal function, and a mitral valve area of 1.4 cm² with an associated dilated LA and a mean trans-valvular gradient of 8 mmHg.

Mitral Stenosis

Mitral Stenosis

• Narrowed MV orifice = prolonged early diastolic mitral inflow and delayed LV filling
• LVEDV and LVEDP are low
• May be associated with LV impairment due to chronic underfilling, muscle atrophy, and scarring of MV apparatus/chordae
• May be associated with RV dysfunction
• Septal shift may impair LV function

How would you manage this patient?

• RATE
• AVOID TACHYCARDIA (decreased time for diastolic filling and increased flow across mitral valve may increase the consequences of LA dilation)
• May need anti-anxiety pre-medication
• Prefer bradycardia
• RHYTHM
• Sinus preferable for atrial kick, usually absent in advanced disease
• PRELOAD
• If LA volume too low, then less likely to fill LV across stenotic valve. If LA volume large, then will predispose to pulmonary edema/right heart failure. Keep euvolemic!
• AFTERLOAD
• If too high, may precipitate mitral regurgitation (often concomitant in RHD)
• CONTRACTILITY
• May need gentle support, particularly if right heart function is compromised.
• Hypoventilation from over-sedation may increase PVR…

Case 4

• An 86 year old male is admitted to the CCU with acute decompensated heart failure. His comorbidities include chronic HFrEF, CAD s/p CABG, a.fib., HTN, HLD, COPD, prior CVA with resultant LUE weakness, atrial fibrillation, DMII, and mild dementia. He was placed on dopamine and diuresed on arrival, but is now only on intermittent furosemide. His TTE on admission showed:
• Dilated LA, dilated RA, LVEF 25-30% with global hypokinesis with regional variations include severe hypokinesis of the apical inferior wall, RV is dilated with moderate decrease in systolic function. The AV is calcified with trace AI, AVA 2.7 cm². There is severe MR with P2 leaflet flail consistent with myxomatous degeneration. Mild-moderate TR. Trace PI.”
• You are asked to provide GA for a MitraClip procedure.

Mitral Regurgitation

Mitral Regurgitation

• Regurgitant flow based on valvular pathology and pressure differential between LV and LA
• Chronic LA pressure increases lead to LA dilatation, and eventually, increased PVR
• RV dysfunction may develop
• LVEDV is chronically high, leading to eccentric LVH
• LV fails over time, may be combined with RV failure

How would you manage this patient?

• RATE
• Prefer high-normal/tachycardia to reduce diastolic filling of LV and eventual increase in regurgitant fraction
• Bradycardia = increases LVEDV and also increases length of systolic contraction, thereby increasing MR fraction
• RHYTHM
• Prefer sinus, though will likely already have high LAP and therefore chronic high LVEDP
• PRELOAD
• Avoid excessive fluid administration
• AFTERLOAD
• Keep low to optimize forward flow from LV, reduce MR
• CONTRACTILITY
• In chronically dilated patients, may need to augment contraction to promote forward flow
• LVEF is not indicative of ”aortic output” in MR

References

• http://www.iars.org/assets/1/7/IARS-RCL10_13.pdf
• Nishimura RA, Otto CM, Bonow RO, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014 Jun 10;63(22):2438-88. doi: 10.1016/j.jacc.2014.02.537. Epub 2014 Mar 3.