Ischemic heart disease

Coronary heart disease

Impaired cardiac function due to inadequate

coronary circulation

Commonest cause- CAD

End result of accumulation of atheromatous plaques in

coronary arteries

Non-atherosclerotic causes Coronary vasospasm- Prinzmetal angina Cardiac syndrome X- common in women Severe LV hypertrophy Severe aortic stenosis or regurgitation Congenital coronary artery anomaly Coronary artery emboli/dissection Increased cardiac demand- tachycardia,

anemia, hyperthyroidism

Risk factors for atherosclerosis Non-modifiable- age, sex, family history Modifiable- Smoking Hypercholesterolemia- LDL, lipoprotein a Hypertension- systolic > diastolic Hyperglycemia- diabetes mellitus Type A behaviour- stress High fibrinogen, factor VII Hyperhomocysteinemia Obesity, sedentary lifestyle CRI

Pathophysiology Atherosclerosis is nearly universal & starts before

adulthood, leading to plaque formation Plaques cause narrowing of coronary arteries Stable plaque causes predictable angina Unstable plaque ruptures, activating clotting system &

thrombus formation, that impairs coronary blood flow causing unstable angina or MI

MI heals with scarring, causing impairing contractility & increasing stiffness, leading to HF- acute/chronic

Ischemic areas & scars are prone to cause ventricular arrythmias, leading to sudden death

Manifestations Asymptomatic Angina- Acute- unstable- unpredictable Chronic- stable- predictable Myocardial infarction- Non ST elevated- NSTEMI ST elevated- STEMI Acute LVF Ischemic cardiomyopathy- CHF Sudden cardiac death

Clinical presentation Angina pectoris- Precordial/retrosternal/epigastric pain Described as tightness, squeezing, choking, indigestion Duration- <20 mins Radiation to left arm, shoulder, jaw Precipitated by exertion, stress, meal, cold, sex Relieved by rest or sublingual nitroglycerin Associated SOB, sweating, nausea, dizziness/syncope Unstable angina- Angina at rest, new-onset, more severe, increased frequency Myocardial infarction- Duration- >20 mins, not relieved by NTG

Evaluation Examination- HR, BP,

±S3/S4, murmur of MR Ix- Disease- ECG-ST elevation/depression, CxR,

Stress test- TMT/radionuclide/ECHO, ECHO- regional wall-motion abnormality, Coronary angiography- CT or conventional, ±IVUS

Risk factors- FBS, lipid profile, creatinine Precipitating factors- Hb, TSH

TMT- Treadmill test Bruce protocol- Increases treadmill speed & elevation every 3 minutes Indication- To confirm diagnosis of angina & determine severity To assess prognosis in patients with known CAD Screen those at high risk of CAD Interpretation- >1 mm flat or downsloping ST depression Severe disease- >2 mm depression, <6 mins. of exercise,

HR <70% predicted for age & hyper/hypotension

Coronary angiography For definitive diagnosis of CAD Indication- if PTCA/CABG an option- Limiting stable angina on adequate medical Rx High-risk disease- ACS or high-risk TMT Concomitant aortic valve disease Older patients undergoing valve surgery Recurrence of angina after PTCA/CABG Cardiac failure with surgically correctable lesion Survivors of SCD or VT Chest-pain or cardiomyopathy of unknown etiology

Treatment Medical- Aspirin- anti-thrombotic-1° & 2° prevention β-blockers- decrease cardiac workload- 2° prevention Statins- plaque stabilization & reduction- 2° prevention ACEI- cardiac remodelling- MI/HF Percutaneous- PTCA ± stent placement Bypass- CABG Experimental- Angiogenic growth factors- FGF-1, VEGF Stem-cell therapy Risk factor modification

Risk factor modification Quit smoking Control HT Control DM Control LDL Reduce stress Reduce weight Active lifestyle

Complication Recurrent ischemia- more after NSTEMI than STEMI Arrythmia- bradycardia, AV block, VT Shock- urgent PCI, ± IABP support Acute MR/VSD- supportsurgical correction Myocardial rupture- kills Heart failure- diuretics, nitrates, dobutamine Aneurysm- surgery, if required Mural thrombus ± embolization-

UFH/LMWHwarfarin

Chronic stable angina Angina occuring predictably on exertion &

relieved by rest or sublingual NTG Normal troponin & CK-MB ECG- Resting ECG- normal During anginal episode-

>1 mm ST depression ± T wave flattening/inversion (ST elevation seen in Prinzmetal angina)

ECHO- for RWMA & LVEF Exercise testing- TMT Coronary angiography, if indicated

Treatment Sublingual NTG- for acute pain Prevention of attacks- Treat/avoid aggravating factors Aspirin (alternative- clopidogrel) Statins β-blockers ± long-acting nitrates ± CCB Risk factor modification

Revascularization Indication- Symptomatic despite adequate medical Rx Left main coronary artery stenosis Triple vessel disease with LVEF <50% Unstable angina Post-MI angina or +ve TMT Modalities- PCI- with stent- bare metal/drug eluting- placement CABG- preferred for L main/TVD with low

LVEF/T2DM

Acute coronary syndrome- ACS Unstable angina & myocardial infarction Unstable angina- cardiac markers- normal Angina at rest, new-onset, more severe, increased frequency With ST depression on ECG & normal Trop-T/I or CK-MB Myocardial infarction- cardiac markers- high Angina- lasts longer & not responsive to S/L NTG Rise of cardiac biomarkers- Trop-T/I & CK-MB With ECG changes- new Q waves/LBBB,

non-ST elevated-NSTEMI or ST elevated-STEMI

ECHO- new loss of viable myocardium or new RWMA

Recoverable myocardium

Hibernating- chronic ischemiaStunned- post-MI

Evaluation- ECHO

Treatment of NSTE ACS Admit- rest, monitoring, ?oxygen Aspirin- 325 mg Clopidogrel- 300 mg stat75 mg OD Anticoagulation- UFH/LMWH Nitrates- for symptomatic relief β-blockers- as tolerated CCB- as add-on to nitrates & β-blockers Statins GP IIb/IIIa inhibitors- for intended early cath/PCI or

for high-risk patients- eptifibatide, tirofiban, abciximab

Indication for early angiography

All patients with ACS, except those with normal stress test-

TMT/ECHO/radionuclide

STEMI Common in early morning ~1/2 have preceding angina- ignored 1/3rd without chest-pain,

specially diabetics e/o HF- poor prognosis Trop T/I- early MI, CK-MB- reinfarction

Treatment Admit- rest, morphine, ?oxygen, monitoring Aspirin + Clopidogrel β- blockers- early, if no contraindications ACEI- early, if no hypotension Statins Reperfusion-

within 12 hours of onset, sooner the better Options- for reperfusion 1° angioplasty- with stenting & GP IIb/IIIa inhibitors Thrombolyt ic therapy- streptokinase, alteplase, tenecteplase-

followed by anticoagulation x 7 days

Post-infarction- no angiography

No complicationsPreserved LVEF >50%

No exercise induced ischemia

Major differences Unstable angina- Trop T/I & CK-MB- normal Rx- Asp + Clopidogrel + UFH/LMWH ± GP IIb/IIIa inhibitors Early coronary angiography- Dx & Rx NSTEMI- Trop T/I & CK-MB- raised Rx- as for unstable angina Early coronary angiography STEMI- Trop T/I & CK-MB- raised Rx- Asp ± Clopidogrel + 1° PCI/Thrombolysis No angiography- post-MI normal LVEF & normal stress test