Essential Concepts in Anatomy and Pathology for by Aida Lai

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Subclavian a. supplied by retrograde blood flow from vertebral a. through carotid a. • Occurs when there is excessive demand from upper limb • Symptoms: transient cerebral ischaemia • Management: surgical bypass Atrial fibrillation • Common causes: – acute MI – hypertension – HF – hyperthyroidism – pulmonary embolism – COPD • Symptoms: – dyspnoea – palpitations – chest pain – dizziness • Signs: – irregularly irregular pulse • Complications: – thromboembolism • Investigations: – ECG (absent P-waves) – echocardiogram – thyroid function tests • Management: – electrical cardioversion – anticoagulation Dextrocardia • Heart displaced to the RHS • Can be associated with situs inversus (in which positions of the major visceral organs are reversed) 38 ESSENTIAL CONCEPTS IN ANATOMY AND PATHOLOGY • Signs: – displaced apex beat to RHS • Investigations: – CXR – ECG Pericarditis • Inflammation of serous pericardium • Mostly caused by viral infection (coxsackie virus, herpes) • Other causes: – bacterial infection (staphylococcus, pneumococcus) – fungal infection – acute MI – rheumatic fever – trauma – drug induced – uraemia – metastatic (lymphoma, breast cancer) – post-radiation • Complications: – cardiac tamponade • Symptoms: – central chest pain that radiates to the arms; pain relieved by sitting forward • Signs: – pericardial friction rub • Investigations: ECG (ST elevation, T-wave inversion, PR interval depression) • Management: – NSAIDs Myocarditis = acute inflammation of myocardium • Mostly caused by viral infection • Other causes: – bacterial infection – fungal infection – idiopathic – drugs (penicillin) – sarcoidosis • Pathological features: – diffuse infiltration of lymphocytes (viral infections) – diffuse infiltration of polymorphonuclear cells (bacterial infections) • Symptoms: – fever – pain CARDIOVASCULAR SYSTEM 39 – fatigue – exertional dyspnoea – palpitations • Investigations: – raised levels of cardiac enzymes in blood – viral Ab titres in blood – ECG – PCR (viral RNA) Infective endocarditis • Endocardial infection leading to inflammation • Usually in sites of underlying valvular/endocardial damage • Risk factors: – congenital valve disease – rheumatic heart disease – prosthetic valve implants – septal defects – IV drug users – haemodialysis – immunosuppression • Symptoms: – fever – malaise – anorexia • Signs: – peripheral septic embolisation: splinter haemorrhage, Roth spots on retina, Osler nodes on soles and palms – finger clubbing – heart murmur • Common causative organisms: – Staphylococcus aureus – Streptococcus viridans – coagulase-negative staphylococci (prosthetic valve patients) • Pathological characteristic: vegetation of platelets and fibrin • Investigations: – serum CRP levels – blood sample collection and culture within 24-hour period before initiating antibiotic treatment – transthoracic echocardiography (TTE) – transoesophageal echocardiography (TOE) – ECG • Management: – IV antibiotics – surgery if infection is persistent • Complications: – valvular incompetence 40 ESSENTIAL CONCEPTS IN ANATOMY AND PATHOLOGY – – – – – myocarditis anaemia glomerulonephritis septicaemia (fever, weight loss) septic emboli (stroke, infarctions) Cardiac tamponade • • • • Fluid accumulates in pericardial space Causes acute heart failure Usually follows trauma to thoracic region Heart is constricted in confined space → venous filling is restricted → cardic output is reduced → shock occurs • Symptoms: – fall in BP – shock – jugular venous distension • Diminished heart sounds • Investigations: – CXR (enlarged heart) – ECG – echocardiogram – cardiac catheterisation Coronary artery disease • Greater than 75% occlusion leads to ischaemia Angina pectoris = pain during physical exertion due to ischaemia of myocardium (a) Stable angina (predictable pain when there is increased demand from the heart) – atheromatous stenosis in coronary arteries (b) Unstable angina (unpredictable pain which may occur at rest) – obstruction of coronary artery due to plaque rupture + thrombosis • Symptoms: retrosternal chest pain radiating to L.

Attachments of internal oblique muscle – origin: lateral two-thirds of inguinal ligament, anterior two-thirds of iliac crest, lateral edge of thoracolumbar fascia to rib 12 – insertion: lower three ribs, xiphoid process, linea alba, pubic crest, pectineal line – muscle fibre direction: superomedial – nerve SS: ventral primary rami of T7–T11, iliohypogastric n. (L1), ilioinguinal n.

SS by L. gastric a. of coeliac trunk. – venous drainage to L. gastric v. and azygos system – innervated by vagus n. and sympathetic n. – lymphatic drainage: post. mediastinal nodes 58 ESSENTIAL CONCEPTS IN ANATOMY AND PATHOLOGY • Nine quadrants of the abdomen: – RUQ (R. hypochondrium), epigastrium and LUQ (L. hypochondrium) – R. flank, umbilical and L. flank – RLQ (R. iliac), suprapubic and LLQ (L. iliac) • Usual causes of RUQ pain: – peptic ulceration, gastritis, hepatitis, pneumonia (R. lung), cholangitis, cholecystitis • Usual causes of epigastric pain: – peptic ulceration, drug-induced gastritis, gastric reflux, biliary colic, acute pancreatitis, abdominal aortic aneurysm (AAA), oesophagitis, angina/MI • Usual causes of LUQ pain: – acute pancreatitis, MI, splenic infarction, gastric reflux, peptic ulceration, pneumonia (L.