Flashcards in Cardiovascular Surgery Deck (211):
What is AI?
What is AS?
What is ASD?
Atrial Septal Defect
What is CABG?
Coronary Artery Bypass Grafting
What is CAD?
Coronary Artery Disease
What is CPB?
What is IABP?
IntraAortic Balloon Pump
What is LAD?
Left Anterior Descending coronary artery
What is IMA?
Internal Mammary Artery
What is MR?
What is PTCA?
Percutaneous Transluminal Coronary Angioplasty (balloon angioplasty)
What is VAD?
Ventricular Assist Device
What is VSD?
Ventricular Septal Defect
What is stroke volume?
mL of blood pumped per heartbeat
What is cardiac output?
Amount of blood pumped by the heart each minute
What is cardiac index?
CO/BSA, BSA = body surface area
What is ejection fraction?
Percentage of blood pumped out of the left ventricle (SV/EDV)
What is compliance?
(Change in volume)/(Change in pressure)
What is SVR?
Systemic Vascular Resistance
(MAP - CVP)/(CO X 80)
What is preload?
Left ventricular end diastolic pressure or volume
What is afterload?
Arterial resistance the heart pumps against
What is PVR?
Pulmonary Vascular Resistance:
(PAmean - PCWP)/(CO X 80)
What is MAP?
Mean Arterial Pressure:
Diastolic BP + 1/3 X (Systolic BP - Diastolic BP)
What is a normal CO?
What is a normal CI?
What are the ways to increase CO?
Mechanical assistance (IABP, VAD)
Inotropes: increase contractility
Rhythm: normal sinus
When does most of the coronary blood flow take place?
What are the 3 major coronary arteries?
3. Right coronary
What are the 3 main cardiac electrolytes?
Ca, K, Mg
What is coronary artery disease?
Atherosclerotic occlusive lesions of the coronary arteries.
Segmented nature make CABG possible.
What is the incidence of CAD?
#1 killer in western world
What are the symptoms of CAD?
If ischemia (due to low flow, vasospasm, thrombus formation, plaque rupture): chest pain, crushing, substernal SOB, nausea, upper abdominal pain, sudden death, fatigue
Who classically gets silent MIs?
Patients with diabetes (autonomic dysfunction)
What are the risk factors for CAD?
HTN, smoking, high cholesterol/lipids, obesity, diabetes, family history
Which diagnostic tests should be performed in CAD?
Exercise stress testing (+/- thallium); echocardiography; localize dyskinetic wall segments; valvular dysfunction; estimate EF; cardiac catheterization with coronary angiography and left ventriculography
What is the treatment for CAD?
Medical therapy (beta-blockers, aspirin, nitrates, HTN medication); PTCA +/- stents; CABG
What are the indications for CABG?
1. Left main disease
2. 2+ vessel disease
3. Unstable or disabling angina unresponsive to medical therapy or PTCA
4. Post-infarct angina
5. Coronary artery rupture, dissection, thrombosis after PTCA
What are the pros and cons of CABG vs. PTCA +/- stents?
CABG: survival improvement for diabetics and 2+ vessel disease, increased short-term morbidity
PTCA: decreased short-term morbidity, decreased cost, decreased hospital stay, increased reintervention, increased post-procedure angina
What procedures are most often used in CABG?
Coronary arteries grafted (usually 3-6); internal mammary pedicle graft and saphenous vein free graft are most often used
Other than IMA and saphenous vein, what vessels are occasionally used for CABG?
Radial artery, inferior epigastric vein
What are the possible complications of CABG?
Hemorrhage, tamponade, MI, dysrhythmias, infection, graft thrombosis, sternal dehiscence, post-pericardiotomy syndrome, stroke
What is the operative mortality from CABG?
1-3% for elective CABG
What medications should almost every patient be given after CABG?
Can a CABG be performed off cardiopulmonary bypass?
Yes, today they are performed with or without bypass
What is post-pericardiotomy syndrome?
Pericarditis after pericardiotomy.
Occurs weeks to 3 months postoperatively.
What are the signs and symptoms of post-pericardiotomy syndrome?
Fever, chest pain, atrial fibrillation, malaise, pericardial friction rub, pericardial effusion, pleural effusion
What is the treatment for post-pericardiotomy syndrome?
NSAIDs +/- steroids
What is pericarditis after an MI called?
What is cardiopulmonary bypass?
Pump and oxygenation apparatus to remove blood from SVC and IVC and return it to the aorta, bypassing the heart and lungs and allowing cardiac arrest for open-heart procedures, heart transplant, lung transplant, or heart-lung transplant, as well as procedures on the proximal great vessels
Is anticoagulation necessary for CPB?
Yes, just before and during the procedure, with heparin
How is anticoagulation reversed?
What are the ways to manipulate cardiac output after CPB?
Rate, rhythm, afterload, preload, inotropes, mechanical (e.g. IABP, VAD)
What mechanical problems can decrease CO after CPB?
Cardiac tamponade, pneumothorax
What is tamponade physiology?
Decreased CO, increased HR, hypotension, increased CVP
What are possible complications of CPB?
Trauma to formed blood elements (esp. thrombocytopenia, platelet dysfunction); pancreatitis (low flow); heparin rebound; CVA; failure to wean from bypass; technical complications (operative technique); MI
What are the options for treating post-op CABG mediastinal bleeding?
Protamine, increased PEEP, FFP, platelets, aminocaproic acid
What is heparin rebound?
Increased anticoagulation after CPB from increased heparin levels, as increase in peripheral blood flow after CPB returns heparin residual that was in the peripheral tissues
What is the method of lowering SVR after CPB?
Warm the patient; administer sodium nitroprusside and dobutamine
What are the options if a patient cannot be weaned from CPB?
Inotropes, VAD, IABP
What percentage of patients goes into AFib after CPB?
Up to 33%
What is the workup of a postoperative patient with AFib?
Rule out PTX (ABG, CT scan), acidosis (ABG), electrolyte abnormality (labs), and ischemia (EKG), CXR
What is a MIDCAB?
Minimally Invasive Direct Coronary Artery Bypass:
LIMA to LAD bypass without CPB and through a small thoracotomy
What is TMR?
TransMyocardial laser Revascularization:
Laser through groin catheter makes small holes (intramyocardial sinusoids) in cardiac muscle to allow blood to nourish the muscle
What is OPCAB?
Off Pump Coronary Artery Bypass:
Median sternotomy but no bypass pump
What is aortic stenosis?
Destruction and calcification of valve leaflets, resulting in obstruction of left ventricular outflow
What are the causes of aortic stenosis?
Calcification of bicuspid aortic valve; rheumatic fever; acquired calcific AS
What are the symptoms of aortic stenosis?
Angina, syncope, CHF, often asymptomatic until late
What is the memory aid for the aortic stenosis complications?
Aortic Stenosis Complications =
Angina Syncope CHF
What are the signs of aortic stenosis?
Murmur (crescendo-decrescendo systolic second right intercostal space with radiation to the carotids); left ventricular heave or lift from left ventricular hypertrophy
What tests should be performed for aortic stenosis?
CXR, ECG, echocardiography, cardiac catheterization (needed to plan operation)
What is the surgical treatment for aortic stenosis?
Valve replacement with tissue or mechanical prosthesis
What are the indications for surgical repair of aortic stenosis?
If patient is symptomatic, valve cross-sectional area is < 0.75 cm^2 (normal 2.5-3.5), or gradient > 50 mmHg
What are the pros and cons of mechanical valve replacement for aortic stenosis?
Mechanical valve is more durable, but requires lifetime anticoagulation
What is the treatment option for aortic stenosis in poor surgical candidates?
Balloon aortic valvuloplasty (percutaneous)
Why is a loud murmur often a good sign?
Implies a high gradient, which indicates preserved LV function
Why might an aortic stenosis murmur diminish over time?
It may imply a decreasing gradient from a decline in LV function
What is aortic insufficiency?
Incompetency of the aortic valve (regurgitant flow)
What are the causes of aortic insufficiency?
Bacterial endocarditis (S. aureus, S. viridans); rheumatic fever; annular ectasia from collagen vascular disease (Marfan's syndrome)
What are the predisposing conditions for aortic insufficiency?
Bicuspid aortic valve, connective tissue disease
What are the symptoms of aortic insufficiency?
Palpitations from dysrhythmias and dilated LV; dyspnea/orthopnea from LV failure; excess fatigue; angina from decreased diastolic BP and coronary flow; Musset sign
What are the signs of aortic insufficiency?
Decreased diastolic BP; murmur (blowing, decrescendo diastolic at left sternal border); Austin-Flint murmur (reverberation of regurgitant flow); increased pulse pressure ("pistol shots", "water-hammer" pulse palpated over peripheral arteries); Quincke sign (capillary pulsations of uvula)
Which diagnostic tests should be performed for aortic insufficiency?
1. CXR (increasing heart size can be used to follow progression)
3. Catheterization (definitive)
What is the treatment for aortic insufficiency?
Aortic valve replacement
What are the indications for surgical treatment of aortic insufficiency?
Symptomatic patients (CHF, PND); LV dilatation; decreasing LV function; decreasing EF; acute AI onset
What is the prognosis for aortic insufficiency?
Surgery gives symptomatic improvement and may improve longevity
What is mitral stenosis?
Calcific degeneration and narrowing of the mitral valve resulting from rheumatic fever in most cases
What are the symptoms of mitral stenosis?
1. Dyspnea from increased LA pressure, causing pulmonary edema
3. Hoarseness from dilated left atrium impinging on the recurrent laryngeal nerve
4. Palpitations (AFib)
What are the signs of mitral stenosis?
Murmur (crescendo diastolic rumble at apex); irregular pulse from AFib caused by dilated LA; stroke caused by systemic emboli from LA
Which diagnostic tests should be performed for mitral stenosis?
What are the indications for intervention for mitral stenosis?
1. Symptoms (severe)
2. Pulmonary HTN and mitral valve area < 1 cm^2
3. Recurrent thromboembolism
What are the treatment options for mitral stenosis?
1. Open commissurotomy (open heart operation)
2. Balloon valvuloplasty (percutaneous)
3. Valve replacement
What is the medical treatment for mild symptomatic patients with mitral stenosis?
What is the prognosis for mitral stenosis?
> 80% of patients are well at 10 years with successful operation
What is mitral regurgitation?
Incompetence of the mitral valve
What are the causes of mitral regurgitation?
Severe mitral valve prolapse; rheumatic fever; post-MI from papillary muscle dysfunction or rupture; ruptured chordae
What are the most common causes of mitral regurgitation?
Rheumatic fever; ruptured chordae; papillary muscle dysfunction
What are the symptoms of mitral regurgitation?
Often insidious and late:
Dyspnea, palpitations, fatigue
What are the signs of mitral regurgitation?
Murmur (holosystolic, apical radiating to the axilla)
What are the indications for treatment of mitral regurgitation?
2. LV > 45 mm end-systolic dimension
What is the treatment for mitral regurgitation?
1. Valve replacement
2. Annuloplasty (suture a prosthetic ring to the dilated valve annulus)
What is artificial valve placement?
Replacement of damaged valves with tissue or mechanical prosthesis
What are the types of artificial valves?
Tissue and mechanical
What are pros and cons of tissue valve replacements?
No anticoagulation but shorter duration (30-40% need replacement in 10 years); good for elderly
What are pros and cons of mechanical valve replacements?
Last longer (> 15 years) but require anticoagulation
What are the contraindications to tissue valve replacement?
Dialysis (calcify), youth
What are the contraindications to mechanical valve replacement?
Pregnancy (or going to be pregnant due to anticoagulation); bleeding risk (alcoholic, PUD)
What is the operative mortality of artificial valve placement?
What must patients with an artificial valve receive before dental procedures?
What is the Ross procedure?
Aortic valve replacement with a pulmonary autograft
What is infectious endocarditis?
Microbial infection of heart valves
What are the predisposing conditions for infectious endocarditis?
Preexisting valvular lesion, procedures that lead to bacteremia, IV drug use
What are the common causative agents of infectious endocarditis?
S. viridans (abnormal valves); S. aureus (IV drug use); S. epidermidis (prosthetic valves)
What are the signs and symptoms of infectious endocarditis?
Murmur (new or changing); petechiae; splinter hemorrhage (fingernails); Roth spots (on retina); Osler nodes (raised, painful on soles and palms); Janeway lesions (similar to Osler nodes but flat and painless)
Which diagnostic tests should be performed for infectious endocarditis?
Echocardiogram, TEE, serial blood cultures
What is the treatment for infectious endocarditis?
Prolonged IV therapy with bactericidal antibiotics
What is the prognosis for infectious endocarditis?
Infection can progress, requiring valve replacement
What is the most common congenital heart defect?
What is a ventricular septal defect?
Failure of ventricular septum to completely close (80% involve membranous portion of the septum), resulting in left-to-right shunt, increased pulmonary blood flow, and CHF if pulmonary to systemic flow is > 2:1.
What is pulmonary vascular obstructive disease?
Pulmonary artery hyperplasia from increased pulmonary pressure caused by a left-to-right shunt (e.g. VSD)
What is Eisenmenger's syndrome?
Irreversible pulmonary HTN from chronic changes in pulmonary arterioles and increased right heart pressures.
Cyanosis develops when the shunt reverses (becomes right-to-left across the VSD)
What is the treatment of Eisenmenger's syndrome?
Only option is heart-lung transplant; otherwise, the disease is untreatable
What is the incidence of VSD?
30% of heart defects (most common defect)
What is patent ductus arteriosus?
Physiologic right-to-left shunt in fetal circulation connecting the pulmonary artery to the aorta bypassing fetal lungs.
Often this shunt persists in the neonate.
What are the factors preventing closure of PDA?
Hypoxia, increased prostaglandins, prematurity
What are the symptoms of PDA?
Poor feeding, respiratory distress, CHF with respiratory infections
What are the signs of PDA?
Acyanotic, unless other cardiac lesions are present; continuous "machinery" murmur
Which diagnostic tests should be performed?
PE; echocardiogram (rule out associated defects); catheter (seldom required)
What is the medical treatment for PDA?
Indomethicin (prostaglandin inhibitor)
What is the surgical treatment for PDA?
Surgical ligation or cardiac catheterization closure at 6-24 months
What is tetralogy of Fallot?
Misalignment of the infundibular septum in early development, leading to the characteristic tetrad:
1. Pulmonary stenosis/obstruction of RV outflow
2. Overriding aorta
3. RV hypertrophy
What are the symptoms of tetralogy of Fallot?
Hypoxic spells (squatting behavior increases SVR and increases pulmonary blood flow)
What are the signs of tetralogy of Fallot?
Cyanosis, clubbing, murmur (SEM at left third intercostal space)
Which diagnostic tests should be performed for tetralogy of Fallot?
CXR (small, "boot-shaped" heart and decreased pulmonary blood flow); echocardiography
What is the prognosis for tetralogy of Fallot?
95% survival at specialized centers
What is IHSS?
Idiopathic Hypertrophic Subaortic Stenosis:
Aortic outflow obstruction from septal tissue
What is the usual presentation of IHSS?
Similar to aortic stenosis
What is coarctation of the aorta?
Narrowing of the thoracic aorta, with or without intraluminal shelf (infolding of the media).
Usually found near ductus/ligamentum arteriosum.
What are the 3 types of coarctation?
1. Preductal (fatal in infancy if untreated)
What percentage of coarctations are associated with other cardiac defects?
60% (bicuspid aortic valve is most common)
What is the major route of collateral circulation with coarctation?
Subclavian artery to the IMA to the intercostals to the descending aorta
What are the risk factors for coarctation?
Turner's syndrome, M > F
What are the symptoms of coarctation?
HA, epistaxis, lower extremity fatigue (claudication)
What are the signs of coarctation?
Decreased lower extremity pulses; systolic murmur (from turbulence across coarctation, often radiating to infrascapular region); continuous murmur (from dilated collaterals)
Which diagnostic tests should be performed for coarctation?
CXR (aortic knob, coarctation, dilated post-stenotic aorta, rib notching is bony erosion from dilated intercostal collaterals); echocardiogram; cardiac catheterization if cardiac defects
What is the treatment for coarctation?
Resection with end-to-end anastomosis; subclavian artery flap; patch graft (rare); interposition graft; endovascular repair (adults)
What are the indications for surgery for coarctation?
Symptomatic patient or > 3-4 years
What are the possible postoperative complications for coarctation?
Paraplegia; paradoxic HTN; mesenteric necrotizing panarteritis (GI bleeding); Horner's syndrome; injury to recurrent laryngeal nerve
What are the long-term concerns with surgery for coarctation?
Aortic dissection, HTN
What is transposition of the great vessels?
Aorta originates from the RV and the pulmonary artery from the LV.
Fatal without PDA, ASD or VSD.
What is the incidence of transposition of the great vessels?
5-8% of defects
What are the signs and symptoms of transposition of the great vessels?
Cyanosis and CHF in neonatal period
Which diagnostic tests should be performed for transposition of the great vessels?
CXR ("egg-shaped" heart contour), catheterization
What is the treatment for transposition of the great vessels?
Arterial switch operation (aorta and pulmonary artery are moved to the correct ventricle and the coronaries are reimplanted)
What is Ebstein's anomaly?
Tricuspid valve is placed abnormally low in the RV, forming a large RA and a small RV, leading to tricuspid regurgitation and decreased RV output
What are the signs and symptoms of Ebstein's anomaly?
What are the risk factors of Ebstein's anomaly?
400 X risk if mother has taken lithium
What are vascular rings?
Represent an anomalous development of the aorta/pulmonary artery from the embryonic aortic arch that surrounds and obstructs the trachea/esophagus.
How are vascular rings diagnosed?
Barium swallow, MRI
What are the signs and symptoms of vascular rings?
Most prominent is stridor from tracheal compression
What are the causes of cyanosis?
Tetralogy of Fallot
Totally anomalous pulmonary venous return
Transposition of the great vessels
What is the most common benign cardiac tumor?
Myxoma in adults
What is the most common location for cardiac tumor?
LA with pedunculated morphology
What are the signs and symptoms of a cardia tumor?
What is the most common malignant cardiac tumor in children?
What is the cause of a thoracic aortic aneurysm?
Vast majority result from atherosclerosis, connective tissue disease
What is the major differential diagnosis of a thoracic aortic aneurysm?
What percentage of patients with a thoracic aortic aneurysm have aneurysms of the aorta at a different site?
What are the signs and symptoms of a thoracic aortic aneurysm?
Most are asymptomatic.
Chest pain, stridor, hemoptysis (rare), recurrent laryngeal nerve compression
How is a thoracic aortic aneurysm most commonly discovered?
Which diagnostic tests should be performed for a thoracic aortic aneurysm?
CXR, CT, MRI, aortography
What are the indications for treatment of a thoracic aortic aneurysm?
> 6 cm diameter; symptoms; rapid increase in diameter; rupture
What is the treatment for a thoracic aortic aneurysm?
Replace with graft; open or endovascular stent
What are the dreaded complications after treatment of a thoracic aortic aneurysm?
Paraplegia; anterior spinal syndrome
What is aortic dissection?
Separation of the walls of the aorta from an intimal tear and disease of the tunica media.
A false lumen is formed and a "reentry" tear may occur, resulting in "double-barrel" aorta.
What are the aortic dissection classifications?
DeBakey classification; Stanford classification
What is a DeBakey type I?
Aortic dissection that involves the ascending and descending aorta
What is a DeBakey type II?
Aortic dissection that involves the ascending aorta only
What is a DeBakey type III?
Aortic dissection that involves the descending aorta only
What is a Stanford type A?
A DeBakey type I or II aortic dissection
What is a Stanford type B?
A DeBakey type III aortic dissection
What is the etiology of an aortic dissection?
HTN; Marfan's syndrome; bicuspid aortic valve; coarctation of the aorta; cystic medial necrosis; proximal aortic aneurysm
What are the signs and symptoms of an aortic dissection?
Abrupt onset of severe chest pain, most often radiating/tearing to the back.
Onset is typically more abrupt than that of MI.
The pain can migrate as the dissection progresses.
What are 3 sequelae of aortic dissection?
1. Cardiac tamponade (Beck's triad)
2. Aortic insufficiency
3. Aortic arterial branch occlusion/shearing, leading to ischemia in the involved circulation (i.e. unequal pulses, CVA, paraplegia, renal insufficiency, bowel ischemia, claudication)
Which diagnostic tests are indicated for aortic dissection?
CXR (widened mediastinum, pleural effusion); TEE; CTA; aortography
What is the treatment for a DeBakey type I or II aortic dissection?
Surgical because of risk of aortic insufficiency, compromise of cerebral and coronary circulation, tamponade, rupture
What is the treatment for a DeBakey type III aortic dissection?
Medical (control BP), unless complicated by rupture or significant occlusions
What is the surgery for an aortic dissection?
Open the aorta at the proximal extent of dissection, and then sew (graft to) intimal flap and adventitia circumferentially (endovascular an option)
What is the preoperative treatment of aortic dissection?
Control BP with sodium nitroprusside and beta-blockers (e.g. esmolol)
what is the postoperative treatment of aortic dissection?
Lifetime control of BP and monitoring of aortic size
What is the possible cause of MI in a patient with aortic dissection?
Dissection involves the coronary arteries or underlying LAD
What is a dissecting aortic aneurysm?
Misnomer (not aneurysm)
What are the EKG signs of atrial fibrillation?
What are the EKG signs of premature ventricular complex?
What are the EKG signs of ventricular aneurysm?
What are the EKG signs of ischemia?
ST elevation; ST depression; flipped T waves
What are the EKG signs of infarction?
What are the EKG signs of pericarditis?
ST elevation throughout leads
What are the EKG signs of RBBB?
Wide QRS and "rabbit ears" or R-R in V1 or V2
What are the EKG signs of LBBB?
Wide QRS and "rabbit ears" or R-R in V5 or V6
What are the EKG signs of Wolff-Parkinson-White?
Delta wave = slurred upswing on QRS
What are the EKG signs of 1st degree A-V block?
Prolonged PR interval (0.2 seconds)
What are the EKG signs of 2nd degree A-V block?
Not all P waves transmit to produce ventricular contraction.
What are the EKG signs of the Wenckebach phenomenon?
2nd degree block with progressive delay in PR interval prior to dropped beat
What are the EKG signs of 3rd degree A-V block?
Complete A-V dissociation.
Random P wave and QRS.
What is Mondor's disease?
Thrombophlebitis of the thoracoepigastric veins
How does an IABP work?
Has a balloon tip resting in the aorta.
Balloon inflates in diastole, increasing diastolic BP and coronary blood flow.
In systole, the balloon deflates, creating a negative pressure, lowering afterload, and increasing systolic BP.
What electrolyte must be monitored during diuresis after CPB?
How is extent/progress of post-bypass diuresis followed?
IO, CXR, JVD, edema, daily weight
What is an Austin-Flint murmur?
Diastolic murmur of AI secondary to regurgitant turbulent flow
Where is the least oxygenated blood in the body?