Lecture 8: Coagulation & CAD

Lecture 8: Coagulation & CAD Hypercholesterolemia · "familial hypercholesterolemia" · common hereditary deficit in LDL receptors ↳ high LDL in bloodstream, low tissue LDL · S&S: high LDL, atherosclerosis, alternate sites of deposition (xanthomas) Coagulation Deficit Causes: · Thrombocytopenia (low platelets) Warfarin cure · Vitamin K deficiency ↳ lack of coagulation factor II, VII, IX, X · Liver disease (eg. infection) · Von Willebrand Disease ↳ insufficiency of vWF (↓clotting,↑bleeding) ↳ Tx: Desmopressin (vasopressin/ADH) · Hemophilia A ↳ factor VIII insufficiency ↳ Tx: Synthetic factor VIII, fresh frozen plasma Factor V Leiden Deficiency · deficiency of the shut-off mechanism of clotting through protein C ↳ Factor V unable to bind factor C · causes high coagulation · triggered by nicotine, or high estrogen Thrombus · a blood clot formed from aggregated platelets and red blood cells that make a plug and cross-linked fibrin · most common in lower extremities but can travel (thromboembolism) · Risk Factors: ↳ venous stasis (decreased mobility, arrhythmias) ↳ high viscosity blood (dehydration) ↳ tissue injury (surgery, inflammation, infection) ↳ Smoking (cytotoxic, oxidation of LDLs) ↳ drug induced (Heparin HITT, birth control) ↳ inherited disorders DVT - Deep Vein Thrombosis · most common site of hypercoagulation · S&S: unilateral leg pain & edema, erythema · ER Tx: Heparin · Tx: LMWH (Sc), Abixaban (PO) Pulmonary Embolism · most commonly caused by DVT embolism · S&S: Chest pain, SOB, low O2 sat · prevention: early mobilization post surgery, compression stockings, anticoagulants · ER Tx: thrombolytics or Heparin · Tx: LMWH (SC), Abixaban (PO) Pulmonary HTN · risks: chronic small pulmonary embolisms, COPD, ideopathic, heart failure · S&S: cough, SOB, lethargy, lower O2 sats · ER Tx: Nipride (nitroprusside), phosphodiesterase inhibitors · Synergistic Tx: decreased preload (Diuretics), prevention of corpulmonale (RHF) Phosphodiesterase Inhibitors · MOA: blocks enzyme phosphodiesterase (PDE) increasing cAMP activity ↳ contraction of myocardial cells * ↳ vasodilation of endothelial cells (relaxation) * · monitor ECG, VS · drugs: Milrinone, Amrinone; Viagra, Revatio (sidenafil) ↳ Tx for acute HF & pulmonary HTN * - En E - Atrial Fibrillation - Risk of Thrombus · disorganized ventricular filling can lead to pooling of blood, low CO · atrial rate > 300 bpm, ventricular rate 80-180 bpm · S&S: dizziness, irregular pulse, pulse deficit · ER Tx: cardioversion (100J electric shock) · Tx: Slow nodal conduction (beta blockers, cardiac CCBs, ASA prophylaxis) · Chronic Tx: Ablation (cauterize bad signals) Coronary Artery Disease (CAD) · narrowing or occlusion of the coronary arteries leading to deprivation of the heart cells (ischemia) ↳ angina → MI ① Chronic Ischemic Disease · ischemia with exertion · S&S: angina · is relieved by nitroglycerin (LAD) · thick, fibrous plaque = stable angina ② ACS: Acute Coronary Syndrome · ischemia without exertion 3 main arteries are checked: the right · is not relieved by drug tx (nitroglycerin) coronary, the left coronary and the circumflex (LAD has same origin as circumflex) · unstable plaque = unstable angina - = - - ACS Continued · S&S: chest pain, back pain, compensation, SOB, GI symptoms, dizziness, LOC ↳ high risk of MI · ECG changes: STEMI, NSTEMI, V-Fib, V-tach (no pulse) · BW: injured myocardial cells leak intrinsic enzymes "biomarkers" ↳ troponin, creatinine Kinase, myoglobin, CKMB Tx of ACS · monitor ECG, O2 · organic nitrates (nitroglycerin), morphine for vasodilation · antiplatelets: ASA, Reopro ↳ thrombolytics < 6 hrs from onset · beta blockers for CO (↓ excitability) · Tx for obstruction: PTCA, CABG (less common) · post: antihypertensives, statins, antiplatelets STEMI vs. NSTEMI · STEMI: coronary artery is blocked, high risk of MI ↳ ECG: ST elevation (not ready to repolarize) ↳ can lead to V-fib very quickly · NSTEMI: NOT coronary artery that is blocked ↳ ECG: ST depression (too quickly repolarized) ↳ not as serious as STEMI · NOTE: STEMI & NSTEMI are not shockable rhythms! Ventricular Fibrillation (V-Fib) · most common arrhythmia in an MI · if no CO, will lose consciousness · shockable rhythm: 200-360J for V-fib or v-tach ↳ shock will stop heart, give epinephrine to restart the heart - Cardiac Tamponade · bleeding into the pericardial space ↳ pressure on heart, ↓CO, HF · causes: PTCA, surgery, cardiac rupture (MI), dissection, trauma · S&S: pulsus paradoxus (alterations of BP on inspiration), SOB · Tx: pericardiocentesis (needle to remove fluid from pericardium) PTCA · "percutaneous coronary angioplasty" · angiogram = visualization · angioplasty = interventional tx ↳ balloon catheter to open up obstruction ↳ risk of rupture