Frank-Starling Relationship: Increased SV accompanying an increased LVEDV
Activation of Sympathetic Nervous System: arterial/venous constriction to maintain BP(a) and increased central return(v), activation of renin-angiotensin-aldosterone system (RAAS) due to decreased renal flow,
Alterations in the Inotropic State, HR, and afterload:Afterload is the tension needed to open the aortic/pulmonic valve and increased during systemic arteriolar constriction and HTN. SHF benefits from tachycardia and DHF benefits from rate control.
Humoral-mediated responses: ANP and BNP release from the heart. Increased levels of vasopressin, endothelial dysfunction, and inflammatory mediator release.
Signs and Symptoms of Heart Failure
Hemodynamic: decreased CO, increased LVEDP, peripheral vasoconstriction, Na and H2O retention, and decreased tissue O2 delivery with a widened a-v O2 difference.
General:dyspnea, fatigue, weakness, organ system dysfunction, tachypnea, moist rales, tachycardia, S3 gallop (ventricular diastolic gallop), bilateral pitting pretibial edema
LV failure: pulmonary edema
RV Failure: systemic venous HTN and peripheral edema.
Heart Failure Diagnosis
Echocardiography: Most useful test to assess abnormalities of the myocardium, valves, or pericardium, and can help measure Ejection Fraction.
NYHA Functional Classification
Class I: Ordinary physical activity does not cause symptoms
Class II: Symptoms occur with ordinary exertion
Class III: Symptoms occur with less than ordinary exertion
Class IV: Symptoms occur at rest
American College of Cardiology (ACC)/American Heart Association (AHA) Classification
Stage A: Patients at high risk of heart failure without structural disease or symptoms
Stage B: Patients with structural disease without symptoms
Stage C: Patients with structural disease with previous/current symptoms of heart failure
Stage D: Patients with refractory heart failure requiring specialized interventions
Avoid: sympathetic stimulation, hypovolemia, and vasodilation
Hypertrophic Cardiomyopathy Preoperative
Updated cardiac evaluation
Continue B-Blockers and Ca Channel Blockers
ICD turned off
Questions regarding family history of cardiac disease/ sudden death
Preoperative medications to decrease anxiety and possible SNS activation
Expansion of intravascular volume may be beneficial.
Hypertrophic Cardiomyopathy Intraoperative
Avoid sudden decrease in SVR: IV induction acceptable
Modest myocardial depression is acceptable
Volatile anesthetic or B-blocker can blunt sympathetic response to DL.
Use smaller tidal volumes and higher RR: PPV can decrease preload and predispose a hypovolemic patient to LVOT obstruction
Insufflation should be done slowly: can cause preload reduction and severe hypotension.
Volatile anesthetics often used in moderate doses: mild depression of myocardial contractility and minimal preload/afterload effects.
Hypotension: Treated with phenylephrine (NOT drugs with B-agonist effects due to increased contractility&HR-ephedrine, dopamine, dobutamine)
Vasodilators should NOT be used to lower BP due to decreased SVR
Maintain normal sinus rhythm.
Primary cardiomyopathy: LV or biventricular dilation, systolic dysfunction, and normal LV wall thickness. Mixed causes with 30% familial. Most common type of cardiomyopathy and the 3rd most common cause of heart failure, and the most common indication for cardiac transplant
S/S: Embolization common
ECG: ST segment and T wave abnormalities and LBBB, cardiac dysrhythmias common
Treatment: Anticoagulation, medical management of chronic heart failure,
Anesthesia: Same as heart failure
Dilated Cardiomyopathy Anesthesia
All types of GA may be used. Opioids effective for inhibiting adrenergic system (delta receptor)
PPV and PEEP: decrease pulmonary congestion and improve arterial oxygenationFluid overload: will worsen heart failure.
Cardiac Transplant patients: Increase in HR can only occur with direct B-agonists (NOT anticholinergics such as atropine).
Primary Cardiomyopathy: Acquired and rare. During 3rd trimester to 5mo after delivery.
S/S: Dyspnea, fatigue, and peripheral edema
Tx: diuretics, vasodilators, and digoxin. ACEIs are teratogenic but can be used following pregnancy. IV Immunoglobulin may be used. Anticoagulation is often recommended.
Secondary Cardiomyopathies with restrictive physiology
Info: Due to systemic diseases that produce myocardial infiltration and diastolic dysfunction (Amyloidosis is the most common).
S/S: LV and RV failure may be present, no cardiomegaly, AFib is common
ECG: conduction abnormalities
Tx: similar to DHF. Diuretics, digoxin, maintain normal sinus rhythm. Anticoagulation w/ low CO or AFib. NO cardiac transplantation.
Anesthesia: Same as cardiac tamponade. Maintain normal sinus rhythm and avoid a significant decrease in HR. Maintain venous return and IV fluid volume.
Info: RV enlargement (hypertrophy/dilation) that may progress to RV failure. Caused by diseases that induce pulmonary HTN (COPD, restrictive lung, respiratory insufficiency)
S/S: Peripheral edema, dyspnea, diastolic murmur due to tricuspid regurgitation
ECG: RA and RV hypertrophy. RA hypertophy has peaked P waves in leads II, III, and aVF. Right axis deviation and RBBB.
Tx: Decrease pulmonary vascular resistance and pulmonary artery pressure. Supplemental oxygen. Diuretics and digitalis. Possible lung transplant due to cardiorespiratory failure.
Cor Pulmonale Preoperative
1. Eliminate and control acute and chronic pulmonary infection
2. Reverse bronchosapsm
3. Improve Clearance of airway secretions
4. Expand collapsed or poorly ventilated alveoli
6. Correct nay electrolyte imbalance
Consider antibiotic prophylaxis for valvular disease
Cor Pulmonale Intraoperative
Induction: any method or drug
Intubation: Ensure adequate depth of anesthesia to prevent bronchospasm
Maintenance: typically volatiles with other drugs. Avoid large amounts of opioid due to ventilatory depression in postoperative period.