Ischemic Heart Disease
Reflects the presence of atherosclerosis in the coronary arteries (Coronary Artery Disease-CAD)
Manifestations of Ischemic Heart Disease
Angina Pectoris, Acute Myocardial Infarction, Sudden Death (likely caused by cardiac dysrhythmias)
Risk Factors for CAD
*male gender and increasing age* Hypercholesterolemia, Hypertension, Smoking Diabetes mellitus, obesity, sedentary life style, family history of premature CAD.
Caused by an imbalance between coronary blood flow (supply) and myocardial oxygen consumption (demand) which can precipitate ischemia
What is the most common cause of myocardial ischemia?
What happens when there is an extreme imbalance between coronary blood flow (supply) and myocardial oxygen consumption (demand)?
Congestive heart failure-(CHF), electrical instability & cardiac dysrhythmias, and myocardial infarction (MI) can result.
how does Angina Pectoris present clinically?
Retrosternal chest pain (described as pressure or heaviness), discomfort typically radiates to the neck, left shoulder, left arm, or lower jaw. Usually induced by physical exertion, emotional tension, and cold weather.
how is angina pectoris diagnosed?
Electrocardiography: ST depression (> 1mm) & T wave inversion Echocardiography: wall motion abnormalities & predicts location of obstructing lesion Nuclear Stress Imaging: assesses coronary perfusion by defining vascular regions in which stress-induced coronary blood flow is limited. Can also est. LV size & function Coronary Angiography: Gold standard. Determines anatomic extent of CAD & LV function (EF).
what is the gold standard for diagnosing angina pectoris?
Coronary Angiography: Gold standard. Determines anatomic extent of CAD & LV function (EF).
what are some treatment options for angina?
Life style modification: Smoking cessation, maintenance of ideal body weight, regular aerobic exercise.
Pharmacologic therapy: Antiplatelet drugs, B-blockers, Calcium channel blockers, ACE inhibitors & Nitrates
Revascularization: Coronary Artery Bypass Grafting (CABG)& Percutaneous Transluminal Coronary Angioplasty PTCA
Nearly all MIs are caused by .....
thrombotic occlusion of a coronary artery
Stenosis > __% required to produce Angina pectoris
diagnosis of an MI requires 2 out of 3 criteria. What are they?
1) clinical history of angina pectoris
2) serial electrocardiographic changes indicative of myocardial infarction (ST segment elevation or ST depression, T wave inversion, bundle branch block)
3) rise and fall of serum cardiac enzyme markers: Troponin T or I-increase within 4 hours after myocardial injury; CK-MB is less specific
what are the symptoms of an MI?
Same as Angina pectoris On Physical exam: Anxiety, sinus tachycardia, hypotension (caused by left or right ventricular dysfunction or cardiac dysrhythmias) Moist rales representing CHF (due to LV dysfunction) Cardiac murmur may reflect ischemic mitral regurgitation.
what are some treatment options for an MI?
Aspirin IV Morphine: pain relief and decrease the stimulus to catecholamine release and increases in myocardial oxygen requirements.
Thrombolytic Therapy: Tissue plasminogen activator (t-PA, streptokinase) within 30-60 min of hospital arrival.
Coronary Angioplasty: within 1-2 hours CABG: reperfusion achieved more quickly with Thrombolytics or PTCA, emergent CABG reserved for patients who’s anatomy precludes PTCA, failed angioplasty, infarct related ventricular septal defect or MR
Adjunctive Medical Therapy: Heparin IV, Beta blockers, ACE inhibitors, nitrate therapy
what are some anesthetic considerations for MIs?
High risk patients should be optimized on preoperative anti-ischemia and anti-hypertension therapy
Control balance between myocardial oxygen supply/demand especially during induction & emergence.
Monitors: ECG, Pulmonary artery catheter, and Transesophageal echocardiography for early detection of ischemia
What are some examples of valvular heart disease?
Mitral Valve Prolapse
How do you evaluate valvular heart disease?
Assess severity of disease
Assess degree of impaired contractility
Assess for the presence of associated major organ system disease (pulmonary, renal, hepatic)
Recognize compensatory mechanisms for maintaining cardiac output (> sympathetic ns activity or ventricular hypertrophy)
Define exercise tolerance to evaluate cardiac reserve
Assess for CHF
Assess for murmurs
AP valves open; so murmurs heard are AP stenosis or MT insufficiency (AS, PS, MR, TR)
MT valves open; so murmurs heard are MT stenosis or AP insufficiency (MS, TS, AR, PR)
symptoms of mitral stenosis
dyspnea on exertion, orthopnea, PND from LV dysfunction (if AR and MR also present significant LV dysfunction)
Mitral stenosis increases pressure where?
how is mitral stenosis diagnosed?
by echocardiography to assess valve orifice
Transvalvular pressure gradient > ___ mmHg=severe MS
Transvalvular pressure gradient > 10 mmHg=severe MS
treatments for mitral stenosis
Prophylaxis against infective endocarditis Diuretics with mild symptoms