Ischemic Heart Disease

ICD

Presentation of IHD

• Can be asymptomatic

• Chest pain or angina pectoris

  • Squeezing, grip-like, heavy, tightness, chest pressure 

  • Not sharp or stabbing

  • Women and elderly can have atypical s/x

• Pain usually lasts few mins 

  • Caused by exertion or emotional stress and relieved with rest 

  • Can be relieved by sublingual NTG

  • If pain lasts longer → concern for STEMI/NSTEMI/UA

Risk Factors

Modifiable	Non-modifiable
→ Hypertension → Hyperlipidemia → Diabetes → Smoking → Physical Inactivity  → Obesity	→ Age (Men > 45, women > 55) → Gender (men, post-menopausal women) → Family h/x of premature heart disease (M<55, F<65)

Progression

Types of IHD	Symptoms	Management
Coronary Artery Disease (CAD)	→ Usually asymptomatic until oxygen demand exceeds supply → Symptoms generally start when >70% of lumen is occluded	→ RF reduction → Monitoring
Chronic Stable Angina	→ “Demand ischemia” → Predictable chest pain upon exertion or stress	→ RF reduction  → Medications → Cardiac catheterization → Monitoring
Acute Coronary Syndromes → STEMI → NSTEMI → Unstable Angina	→ Increased frequency, severity, duration of chest pain → Chest pain at rest and lasting >20 mins	→ Hospital management = revascularization  → RF reduction → Medications → Monitoring

Cardiovascular Testing

Types of Testing	Info
Electrocardiogram (EKG)	→ Non-invasive, quick, easy to perform → Detects arrhythmias, conduction disturbances, myocardial ischemia
Echocardiogram	→ Non-invasive, inexpensive, easy to perform → Trans-thoracic echo (TTE) vs trans-esophageal echo (TEE) → Provides information on structure and function of the heart
Coronary Artery Calcium Scoring	→ Non-invasive, expensive, radiation → Determines presence and extent of coronary calcification  → Increasing evidence to help predict cardiac events
Exercise Stress Test	→ Non-invasive, low-cost, some expertise to perform  → Monitors BP, HR, EKG as speed and incline increase → Indications: Determine presence of myocardial ischemia or arrhythmias/conduction abnormalities  → Often used with nuclear perfusion imaging
Pharmacologic Stress Test	→ Same indications as exercise stress test → OFten used with nuclear perfusion imagin → Used if pt cannot run on treadmill → Medications used to dilate coronary arteries: Dobutamine Adenosine  Dipyridamole Regadenoson
Myocardial Nuclear Perfusion Imaging	→ Involves injection of radiopharmaceutical during stress test  → Compares blood flow between stress adn rest → Identifies areas of reversible ischemia
Cardiac Catherterization	→ Invasive, expensive, requires cardiologist expertise  → Best method to visualize coronary arteries  → AKAk coronary angiography or percutaneous coronary intervention if intervention performed → Complications: 0.2% - 0.3% risk of major complications (MI, stroke, death) Contrast-induced nephropathy

Treatment for Chronic Stable Angina

Risk Factor Reduction 

Risk Factor	Goals of Therapy
Hypertension	→ Control BP by guidelines
Hyperlipidemia	→ Control lipids by guidelines
Diabetes	→ Control BG by guidelines
Smoking	→ Smoking Cessation
Physical Activity	→ 30 minutes 5-7 times per week
Others	→ Maintain BMI 18-25 kg/m → Moderate alcohol consumption → Dietary modifications

Myocardial Oxygen Demand (MVO2)

• Angina usually due to imbalance of oxygen demand and supply

• Major determinants

  • HR

  • Contractility 

  • Intramyocardial wall tension during systole 

• Cannot be measured directly 

• Estimate is Double Product Equation: DP = HR X SBP

Risks and Factors

• Risk Stratification: 

Detailed H/X and physical (RF) ⇒ EKG / Echocardiogram → Stress testing → Coronary angiogram (Catherterization) 

• Exacerbating Factors:

Medications	Cardiac	Other
→ Vasodilators → Thyroid replacement → Vasoconstrictors	→ Tachyarrhythmias → Bradyarrhythmias → Valvular Heart Disease	→ Anemia → Uncontrolled HTN → Hyperthyroidism  → Hypoxemia

Treatment Recommendations

• Risk Factor Reduction

• Aspirin 81 mg indefinitely 

  • Clopidogrel if ASA is C/I

• Anti-anginals 

• Interventional 

  • Percutaneous Coronary Intervention (PCI)

  • Coronary artery bypass graft (CABG)
    

Anti-Anginals

	BB	CCB	Nitrates	Ranolazine (Renexa)
Line of Tx	→ 1st line of choice for chronic prophylaxis  Esp. if post MI  Lack of tolerance, anti-HTN  → Most beneficial in high resting HR and fixed anginal threshold  → Cardioselective BB most commonly used, but not required	→ Use instead of BB if pt is C/i or intolerance to BB → Add to BB if pt still symptomatic with BB  → General considerations Use non-DHp CCb if high HR Use DHP if lower HR	Short Acting: →  Infrequent acute attacks (few times/month) → Prophylaxis with activities that precipitate angina (taken 5-1 minutes prior) Long Acting: → Add on Tx to BB or CBB if ineffective → Monotherapy only if BB or CCB C/I or intolerable (will cause compensatory tachycardia)	Reserved for pts with inadequate response to other anti-anginal medications
Drugs	Selective B1: → Metoprolol Tartrate (Lopressor): 25-400mg  → Metoprolol Succinate (Toprol XL): 25-400 mg  → Atenolol (Tenormin): 25-100mg  → Nebivolol (Bystolic): NO stim(A1)  → Bisoprolol  → Acebutolol  Nonselective B1 and B2: → Carvedilol(Coreg): 6.25-50mg, A1 → Propranolol (Inderal) → Labetalol (Normodyne), A1 Act.  → Nadolol	DHP: → Amlodipine (Norvasc): 2.5-20mg  → Nifedipine (Procardia) : 60-120mg → Felodipine  → Isradipine → Nisoldipine  Non-DHP: → Diltiazem (Cardizem): 120-480 mg  → Verapamil (Calan, Verelan): 120-480mg	Short Acting: → SL tablets or spray  → Nitroglycerin SL (Nitrostat): 0.4 mg SL PRN Long Acting:  → Oral or transdermal patches  → Isosorbide mononitrate (Imdur)
Effects on MVO2	↓ HR, contractility, BP	→ Vasodilation of systemic and coronary arteries → Depression of myocardial contractility  → Depression of conduction velocity of SA and AV nodes	→ Systemic venodilation: dilation of the veins leads to decreased ventricular preload → Direct coronary vasodilation: allows more blood to circulate to heart during diastole	Does not affect HR, inotropy, hemodynamics, or coronary blood flow
C/I	→ Hypotension → Bradycardia & heart block → Decompensated HF → Uncontrolled asthma	→ Non-DHP: bradycardia and heart block → DHP: hypotension	Use of phosphodiesterase-5 inhibitors within 24-48 hrs  Sildenafil, tadalafil, vardenafil  Hypotension leads to dangerous drop in BP	→ Pre-existing QT prolongation → QT prolongation medications → Hepatic Impairment → Potent 3A4 inhibitors
Monitor / Counseling	HR, BP  Goal resting HR for angina = 50-60 bpm Goal max HR = 100 bpm		BP/HR  Counseling: → Headache → Nitrate free interval at least 8 hrs per day to decrease development of tolerance → SL tablets Keep in original container Call 911 if persistent chest pain after 3 tabs (or sprays)	QT prolongation  SE: → dizziness, headache, constipation, nausea