Nicole Weiss, MD Tulane University, December 13, 2012

Time Crunch…  Valvular Heart Disease  Hypertrophic Cardiomyopathy  The Transplanted Heart  Congenital Heart Disease  Simple Shunts  Complex Shunts  Antibiotic Prophylaxis  Pacemaker Classification

New York Classification of Functional Heart Disease Class I: Asymptomatic except during Severe Exertion Class II: Symptomatic with Moderate Activity Class III: Symptomatic with Minimal Activity Class IV: Symptomatic at Rest

Valvular Disease

Mitral Stenosis  Most common etiology is rheumatic disease  Symptoms develop years later when mitral valve area decreases from 4-6 cm 2 to less than 2cm 2  Prone to Pulmonary Hypertension & Pulmonary Edema as Left Atrial Pressures Increase

Anesthetic Goals for Mitral Stenosis  Pulmonary Artery Catheter?  Yes, pulmonary artery pressures help guide fluid management  Patients are prone to volume overload and pulmonary edema  SVR?  High, flow through the stenotic valve is limited and the heart cannot compensate for decreases in preload  Heart Rate?  Normal Sinus Rhythm, Filling is dependent on atrial kick, but too low and the cardiac output may not be sufficient  Supraventricular Tachycardia may cause sudden hemodynamic collapse

Clinical Correlations  Ephedrine or Phenylephrine?  Phenylephrine  Ketamine?  Bad  Pancuronium?  Bad  Neuraxial Anesthesia?  Spinal probably not the best choice  Epidurals give us time to stabilize the hemodynamics

Aortic Stenosis  Critical Valve Area: cm2  Similar management to MS  Management Goals:  Normal Intravascular Volume  High SVR  Normal Sinus Heart Rate (60-90)  Cardiac Output does not increase with exertion  Myocardial Oxygen Demand High (Hypertrophied Ventricle)

Aortic & Mitral Regurgitation  Management Goals:  Fast Heart Rate (80-100)  Decreased Afterload to Promote Forward Flow  Mitral Regurgitation Pulmonary Artery Waveform:  Large V Wave, Rapid Y Descent

A 70 y/o male with severe aortic stenosis has a preinduction HR of 63 and BP of 125/70. Following induction, his HR is 90 and BP is 85/45. The EKG has a new ST Elevation. Drug of Choice? 1. Epinephrine 2. Isoproterenol 3. Calcium Chloride 4. Phenylephrine 5. Ephedrine

Pulse Variations  Bisferiens Pulse  Characteristic of Aortic Regurgitation  First Systolic Peak=LV Ejection  Second Systolic Peak= Reflected Pressure Wave in the Periphery  Pulses Tardus et Parvus  Characteristic of Aortic Stenosis  Delayed Pulse Wave with a Diminished Upstroke

Hypertrophic Cardiomyopathy

 Diastolic Dysfunction  Dynamic Obstruction of the LV Outflow Tract (25% of patients)  Caused by Narrowing in the Subaortic Area by Systolic Anterior Motion (SAM) of the Anterior Mitral Valve Leaflet Against the Hypertrophied Septum  Supraventricular & Ventricular Arrhythmias

Anesthetic Management  Factors that Worsen Obstruction:  Enhanced Contractility  Decreased Ventricular Volume  Decreased LV Afterload  B-Blockers & Ca-Channel Blockers  Amiodarone for Arrhythmias  Ideal Anesthetic: Halothane  Decreases Myocardial Contractility  Maintains SVR  Avoid: Nitrates, Digoxin, Diuretics

The Transplanted Heart

 Denervated  No sympathetic or parasympathetic input  Resting Heart Rate (no vagal)  Responsive to catecholamines  Low cardiac output, slow to pick up  EKG shows two P waves

Pharmacology  Direct agents are the best:  Epinephrine & Isoproterenol  Indirect vasopressors also work, but are dependent on catecholamine stores  Heart rate is NOT affected by:  Anticholinergics  Pancuronium  Meperidine  Opiods  Cholinesterase Inhibitors

A patient has a heart rate of 110 after heart transplant. The most likely etiology is: 1. Altered Barorecepter Sensitivity 2. Cardiac Denervation 3. Compensation for a fixed Stroke Volume 4. Cyclosporine 5. Prednisone

Left to Right (Simple) Shunts

Qp : Qs=  Ratios < 1  Right->Left  Ratios >1  Left->Right  Ratios = 1  No Shunting or Bidirectional Shunts of Equal Magnitude (CaO2-CvO2)/(CpvO2-CpaO2)

Factors Altering Shunts  SVR  Increase:  Phenylephrine, Norepinephrine, Ketamine  Decrease:  Propofol, Inhaled Agents (Iso, Sevo, Des), Dexmetomidine  Nitroprusside, Nitroglycerin, Nicardipine, Milrinone, Fenoldopam, Adenosine  PVR  Increase:  Hypercapnea, Acidosis, Hypoxemia, Positive Pressure Ventilation, Hypothermia, Reactions to the ETT

Shunts & Induction of Anesthesia  R->L Shunt  Longer Inhalation Induction  Shorter IV Induction  L->R Shunt  Shorter Inhalation Induction  Longer IV Induction

Compared with a normal patient, which of the following is true in a patient with a right->left intracardiac shunt? (More than one answer) 1. Inhalation Induction is slowed 2. Induction rate for halothane is affected more than the induction rate for nitrous oxide 3. IV induction is more rapid 4. Increased doses of IV agents are required

Atrial Septal Defects  Ostium Secundum  Most Common  Area of Fossa Ovalis  Usually Isolated Defects  Usually Asymptomatic  Ostium Primus & Sinus Venosus  Associated with Other Cardiac Defects  Large Ostium Primum can cause a Large Shunt and Mitral Regurgitation  Atrioventricular Septal Defects  Endocardial Cushion Defects  Contiguous Atrial & Ventricular Defects  Associated with Downs  Large Shunts

Ventricular Septal Defects  Most common congenital defect  Small VSDs often close during childhood  Restrictive are associated with small L->R  Large defects produce large L->R shunts that vary with SVR and PVR  Large VSDs are surgically repaired before pulmonary disease and Eisenmenger develop

Patent Ductus Arteriosus Closes within 15 hrs Factors that Keep Open: High Prostaglandins Hypoxemia Nitric Oxide Factors that Close Low Prostaglandins High Oxygen Endothelin-1 Norepinephrine Ach Left Untreated-> Eisenmenger

Right to Left (Complex) Shunts

Tetralogy of Fallot 1.RV Obstruction (Infundibular Spasm) 2.RVH 3.VSD 4.Overriding Aorta 5.20% have Pulmonic Stenosis

Management of Tetralogy  Two components of Shunt (R->L)  Fixed (Obstruction of the Outflow Tract)  Dynamic (PVR: SVR or Qp:Qs)  Decrease the Shunt  Propranolol  Propranolol decreases infundibular spasm  SVR  Keep SVR high!

Tetralogy of Fallot…  Four Parts?  RV Outflow Obstruction, RVH, Overriding Aorta, VSD  Ketamine?  Maintains SVR  Propranolol?  Decreases Infundibular Spasm  Prostaglandin E1?  Keeps PDA open  Augments Pulmonary Blood Flow in the case of Right Ventricular Obstruction

Tricuspid Atresia  Small RV  Large LV  Limited Pulmonary Blood Flow  Arterial Hypoxemia  ASD: Mixes oxygenated with deoxygenated, Ejects through LV  Pulmonary Blood Flow is via a VSD, PDA, or Bronchial Vessels

Fontan Procedure Anastamosis of the Right Atrial Appendage to the Pulmonary Artery Used to correct decreased pulmonary Artery blood flow or for patients with a single ventricle  After CPB:  Maintain increased right atrial pressures to  Facilitates pulmonary blood flow  Patients with a Fontan:  Monitor CVP (which equals the PAP )  Follow intravascular fluid volume, pulmonary pressures and detect LV impairment

Transposition of the Great Arteries  Parallel Systems  Treatment:  Prostaglandin E  Balloon Atrial Septoplasty  Decrease PVR, Increase SVR

Hypoplastic Left Heart  LV Hypoplasia  MV Hypoplasia  AV Atresia  Aortic Hypoplasia  Prone to Ventricular Arrhythmias  Increased Pulmonary Blood Flow-> Systemic & Myocardial Ischemia  Delicate Balance Between PVR & SVR

Truncus Arteriosus  Increased Pulmonary Blood Flow->  Myocardial Ischemia  Management:  Phenylephrine & Fluids  PEEP

Anastamosis of the right atrium to the pulmonary arter (Fontan procedure is useful surgical treatment for each of the following except: 1. Tricuspid Atresia 2. Hypoplastic Left Heart Syndrome 3. Pulmonary Valve Stenosis 4. Truncus Arteriosus 5. Pulmonary Artery Atresia

Appropriate therapy for “tet spells” include (may be more than one):  1. Propranolol  2. Dobutamine  3. Phenylephrine  4. Ephedrine

Antibiotic Prophylaxis  High Risk:  Previous Infective Endocarditis  Prosthetic Valves  CHD (some)  Transplants  Procedure Type  None for GI/GU  Bronchoscopy- depends  Dental Procedures- depends

Pacemaker Codes  Chamber Paced  OAVD  Chamber Sensed  OAVD  Response to Sensing  OTID