Surgical Congenital & Acquired Heart Diseases PDF

Congenital and Acquired Heart Disease By Prof. Mohamed Aboelkheir Student learning outcomes List different heart pathologies Identify how different heart pathologies can affect the heart’s functional capacity...

Congenital and Acquired Heart Disease By Prof. Mohamed Aboelkheir Student learning outcomes List different heart pathologies Identify how different heart pathologies can affect the heart’s functional capacity Describe cogential heart diseases Understand the role of surgery in heart disease  Case based discussion A 45-year-old tall, thin, male has acute onset of chest pain radiating into the back. In the emergency room his right radial pulse is bounding but his femoral pluses are absent. The most likely diagnosis is? (a)congestive heart failure. (b)Transient ischemic attacks (TIA). (c) Aortic dissection. (d)Ventricular fibrillation. (e)Acute MI.  Coronary artery disease(CAD): * Definition: clinical syndrome results from the progressive blockage of the coronary arteries by atherothrombotic disease → inadequate myocardial perfusion to meet metabolic demand (ischemia). * Significant risk factors include: ❑ Hypertension. ❑ Dyslipidemia (especially high LDL, low HDL, elevated Lp (a) or apoB, or triglycerides). ❑ Diabetes mellitus. ❑ Obesity NB: A combination of the above being termed metabolic syndrome. ❑ Cigarette smoking. ❑ Family history of premature CAD.  Coronary artery disease: Progressive compromise in luminal diameter → usually produces a pattern of chronic stable angina, commonly referred to as “stable ischemic heart disease (SIHD). Plaque rupture with superimposed thrombosis is responsible for most acute coronary syndromes (ACS), which include classic “ unstable angina”, non‐ST‐elevation myocardial infarctions (non‐STEMI), and ST‐elevation infarctions (STEMI). Ischaemic heart disease:- * Pathophysiology: Usually caused by atherosclerosis of the coronary arteries. What is the atherosclerosis ? It is a process characterized by the presence of focal intimal elevation & blockage in large and medium sized arteries, caused by accumulations of cholesterol (atherosis) and a proliferation of connective tissue (sclerosis) in subintimal space. Risk factors for IHD Advancing age Male gender Hyperlipidaemia Diabetes mellitus Hypertension Smoking Family history of IHD Obesity Reduced physical activity Ischaemic heart disease:- * Clinical manifestations Chest pain or angina, breathlessness, fatigue, palpitations and syncope. * Investigations 1- Resting electrocardiography (ECG): essential in the acute clinical setting, however, it may be normal even in the presence of severe multivessel coronary heart disease. 2- Cardiac isoenzymes and troponins: Troponin T and I, markers of myocardial damage, are more specific and may aid in a rapid diagnosis as well as having prognostic implications. Ischaemic heart disease:- 3- Echocardiography: it is valuable for the evaluation of ventricular function and regional wall motion abnormalities, as well as valvular lesions. 4- Coronary angiography: ‘Gold standard’ for imaging the anatomy , aids in diagnosis of ischemia & its prognosis. Demonstrates extent, severity and location of stenoses. Reduction in diameter of > 70% is considered severe. Demonstrates quality and size of distal arterial tree. Evaluates suitability for surgery. Coronary vessels  Coronary angiography Right coronary Left coronary Ischaemic heart disease Indications for surgery in IHD: > 50% stenosis of the left main stem (‘critical left main stem disease’) > 70% stenosis of the proximal left anterior interventricular artery All three main coronary arteries diseased (‘triple-vessel disease’) Poor ventricular function associated with coronary artery disease. → Coronary Artery Bypass Graft (CABG) Selection of conduit: Venous grafts The long saphenous vein is the most common vein used as a conduit as it is straight forward to harvest, provides good length and is easy to handle. The 10-year patency rate for long saphenous vein grafts is 50–60%. Arterial grafts The left internal mammary (thoracic) artery (LIMA) or radial artery.  > 70% stenosis of proximal left anterior Left main coronary artery stenosis > 50%. descending (LAD) and proximal circumflex artery (PCA) Reversed SVG Radial artery Harvest Left internal mammary artery CABG surgery valvular heart disease Treatment of valvular heart disease Surgical Treatment : depending on the underlying pathology and the severity of disease → whether to repair or to replace the diseased valve. Types of Prosthetic Valve replacement: Mechanical (synthetic): Advantage : Durability → lifelong. Disadvantages : Needs life long anticoagulation + susceptible to infection. Biological: Biological valves may be homograft (or allograft) valves, removed from cadavers; autografts, a patient’s own valve; heterografts (or xenografts) prepared from animal tissues (commonest) Advantage: less risk of clots formation (so life long anticoagulant isn’t usually necessary). Disadvantages: less durable than synthetic (wear out a bit faster than mechanical). Valvular heart disease: Postoperative management: Antibiotic prophylaxis to guard against endocarditis. Anti-thrombotic therapy. Complications: 1- Structural valve failure: common in biological > mechanical (degenerative changes). 2- Thromboembolism: Most common complication. The risk of thromboembolism is greater with a valve in the mitral position (mechanical or biological) than with one in the aortic position (Improved haemodynamic function of aortic valve lowers the risk). 3- Prosthetic valve endocarditis: ✓ The incidence is 2–4%. ✓ Symptoms of septicemia, appearance of a new murmur or a septic embolus. ✓ The most common organisms that can lead to PVE are Staphylococcus epidermidis and Staphylococcus aureus.  Aortic aneurysm: ❑ Defined as a dilatation at least 1.5 times normal. ❑ AEtiologies: Degeneration (atherosclerosis, fibromuscular dysplasia), infection (syphilis), trauma, inflammation (Takayasu), connective tissue diseases (Marfans, Ehlers-Danlos syndrome), and congenital (Turner syndrome). ❑ Risk factors include HTN, high cholesterol, other vascular disease, family history, smoking (strongest predictor of rupture), gender (males > females), and age (≥ 65 yrs). ❑ Complications: rupture, thrombosis, embolism, fistula, and mass effect. Ruptured aneurysm leads to hypotension and severe, tearing abdominal pain that radiates to the back, iliac fossae, or groin and syncope with pulsatile abdominal mass. ❑ Usually asymptomatic and discovered incidentally.  Aortic dissection: - CT is the best initial test for hemodynamically stable patient but not in impending rupture. Involves the ascending aorta Does not involve the ascending aorta - Trans oesophageal ECHO(TEE) Aortic dissection Presentation: Surgical TTT: * With type A → Surgical repair (by prosthetic graft). * With type B → Endovascular repair is preferred over open surgical repair. Congenital Heart Disease  Classification of congenital heart disease Cyanotic Heart Disease Acyanotic Heart Disease Decreased pulmonary flow: Left-to-right shunt: ▪ Tetrology of Fallot. Ventricular Septal Defect ▪ Tricuspid atresia. Atrial Septal Defect Increased pulmonary flow: Atrioventricular Septal Defect ▪ Transposition of the Great Arteries PDA ▪ Truncus Arteriosus Obstructive lesions: Aortic stenosis Coarctation of the Aorta Cyanotic heart disease: Truncus Arteriosus ❑Infants with truncus arteriosus usually are in distress in the first few days of life because of the high amount of blood going to the lungs which makes the heart work harder. ❑Surgery is needed to repair the heart and blood vessels. This is usually done in the first few months of life. Cyanotic heart disease: Transposition of the Great Arteries Risk factors include mothers with preexisting diabetes and, rarely, DiGeorge syndrome. Typically presents within the first few hours after birth. Best initial treatment: Intravenous PGE1 to maintain or open the PDA. Most definitive treatment: Surgical correction (arterial switch operation). Cyanotic heart disease Tetrology of Fallot Consists of :- Pulmonary stenosis → right ventricular outflow tract obstruction (RVOT). Overriding aorta. RVH. VSD. Best initial treatment: If there is severe RVOT obstruction or atresia, one must emergently administer PGE1 to keep the PDA open. This should be done in conjunction with surgical consultation. Acyanotic heart disease Septal defects Atrial septal defect (ASD). Ventricular septal defect (VSD). Atrioventricular septal defect (AVSD). Most small ASDs/VSDs close spontaneously and do not require treatment. Follow-up echocardiography is scheduled based on size of ASD/VSD and physical examination. If congestive heart failure (CHF) develops, best initial treatment involves medical management of CHF, using diuretics. Surgical correction is indicated in symptomatic patients who: Failed medical ttt.