DENT3005 L2 Cardiology for Dental Practitioners PDF

Miss Magdalen Foo Discipline lead in Oral Maxillofacial Surgery Circulatory system 1. Cardiovascular system 2. Lymphatic system Cardiovascular system Deliver oxygen and metabolic substrates to tissues and remove products of metabolism .  Carbon dioxide resulting from...

Miss Magdalen Foo Discipline lead in Oral Maxillofacial Surgery Circulatory system 1. Cardiovascular system 2. Lymphatic system Cardiovascular system Deliver oxygen and metabolic substrates to tissues and remove products of metabolism .  Carbon dioxide resulting from metabolism of oxygen within tissues is removed and transported to the lungs  In the lungs, carbon dioxide is removed from the blood and exhaled  Oxygenated blood travels from the lungs and is distributed to the tissues of the body  Lymphatic system Part of the circulatory system, comprising a network of lymphatic vessels that carry lymph, a fluid containing infection-fighting white blood cells that has leaked from the blood vessels into the tissues and empties back into the blood stream via the lymph nodes  Right and left coronary arteries  Parasympathetic and sympathetic nerve supply  Sinoatrial node  Atrioventricular node  Atrial pathways  Bundle of His  Ventricular muscle  Purkinje fibres  Between ventricular systole and beginning of next atrial cycle, blood surge along arteries by sequential tightening of elastic layer  Between systoles, ventricles relax, which is diastole  Maximal pressure of blood in the arteries occur during peak of ventricular contraction (systole) , whilst minimal pressure occurs at the end of ventricular contraction (diastole)  CO = Stroke Volume (SV) X Heart Rate (HR)  SV determined by 1.preload 2.afterload 3.contractility  Strength of cardiac contraction is dependent on initial fibre length. Increased fibre length changes calcium sensitivity of the myofilament. Beyond optimal fibre length, contraction is impaired  Total blood volume is 5L in 70kg male  Distribution in erect is 65% veins, 13% arteries, 2% arterioles, 5% capillaries, 15% central volume Blood pressure - systolic pressure over diastolic pressure Normal range at rest 100-140 mmHg systolic 60-90 mmHg diastolic  Pressure of blood on walls of artery as heart pumps blood around body  Arteries closest to the heart have thick elastic layer to better withstand force of blood surge  F Fast, neural mediated baroreceptor Slower, hormone regulated renin- mechanism angiotensin-aldosterone system  Major cause of death in Australia  45,392 deaths attributed to CVD in 2015  Kills one Australian every 12 minutes  Affects one in six Australians or 4.2 million.  Lower socioeconomic groups, Aboriginal and Torres Strait Islander people and those living in remote areas had the highest rate of hospitalisation and death resulting from CVD in Australia  Coronary artery disease Stable angina, unstable angina, myocardial infarction  Central crushing chest pain, radiating to neck/mandible/arm  Occur with exercise or stress  Unstable angina occur at rest/minimal exertion  Myocardial infarction more severe and longer duration, not relieved by Glyceryl trinitrate (GTN)  Risk factors – high blood pressure, smoking, diabetes, obesity, high cholesterol, excess alcohol  Prevention by diet, regular exercise, maintain healthy weight, no smoking  Medications - antiplatelet, beta blocker, glyceryl trinitrate  Sudden stop in effective blood flow due to failure of heart to contract effectively  Loss of consciousness, absent breathing  Death within minutes if CPR (cardiopulmonary resuscitation) not commenced  Coronary artery disease, major blood loss, lack of oxygen, hypokalaemia, heart fail, long QT syndrome  Blood pressure in arteries persistently elevated  Major risk factor for coronary heart disease, cerebrovascular accident, heart failure, peripheral vascular disease, vision loss and chronic kidney disease  Lifestyle factors – excess salt, excess body weight, smoking, alcohol therosclerosis  Narrowing of the peripheral arteries to the legs, arms, and feet  Intermittent claudication, ischemic rest pain, ulceration or gangrene  Renal artery stenosis is the narrowing of one of the renal arteries, most often caused by atherosclerosis or fibromuscular dysplasia  Narrowing of the renal artery can impede blood flow to the target kidney, resulting in reno-vascular hypertension  Sudden death of brain cells due to lack of oxygen when blood flow to the brain is impaired by blockage  Heart cannot pump (systole) nor fill (diastole) adequately  Symptoms include shortness of breath, fatigue, swollen legs, rapid heartbeat  Reduce salt, limit fluid, medications  Problems with electrical conduction system  Heartbeat is irregular, too fast, too slow  4 main types – extra beats, supraventricular tachycardia, ventricular arrhythmias, bradyarrhythmias  Asymptomatic or palpitations or pause between heartbeats  Lightheaded, shortness of breath, chest pain  Predispose to complications e.g. stroke, heart failure, cardiac arrest  Treatment include medications, pacemaker, surgery  Uncommon  Staphylococcus aureus followed by Streptococci of the viridans group and coagulase negative Staphylococci are the three most common organisms responsible  May affect damaged heart valves, prosthetic heart valves, coarctation of aorta, patent ductus arteriosus, ventricular septal defect  Minimise bacteraemia / antibiotic prophylaxis  Prosthetic cardiac valve  Extractions  Previous infective  Periodontal surgery, endocarditis subgingival scaling and  Cardiac transplantation root planing with subsequent  Replanting avulsed valvulopathy teeth  Other surgery e.g.  Rheumatic heart implant placement, disease in Indigenous apicectomy, incision Australians only and drainage of dental  Congenital heart abscess, biopsy disease Cardiac condition for which Dental procedures where antibiotic prophylaxis antibiotic prophylaxis recommended always required  Amoxycillin 2g oral 1 hour before procedures Penicillin hypersensitivity, long term penicillin, recent penicillin or other Beta-lactam more than once in the previous month  Clindamycin 600mg oral 1 hour before procedure  Cyanotic and non-cyanotic  Problem in structure present at birth  Signs and symptoms depend on specific problem  Cause often unknown  Risk factor- parent with a congenital heart defect  Associated with genetic conditions e.g. Down syndrome  Infective endocarditis risk Coronary artery Coronary angiogram  Bypass blocked section of a coronary artery and deliver oxygen to the heart  Artificial valves may be tissue or mechanical  Patients with mechanical valves are placed on life-long warfarin  Patients with prosthetic heart valves require antibiotic prophylaxis for dental procedures which produce bacteraemia  Pre-transplant, eradicate potential source of infection and optimise oral hygiene  Post-transplant, treatment complicated by Immunosuppression Steroid therapy Risk of infective endocarditis Gingival overgrowth Hepatitis, HIV infection Beta-blocker e.g. Atenolol, Propranolol, Sotalol Oral side effects – dry mouth , lichenoid reaction  Side effects of Beta-blocker ; dry mouth , lichenoid reaction Diuretics e.g. Furosemide, Spironolactone, Chlorothiazide lower blood pressure by increasing urine output Oral side effects – dry mouth  ACE inhibitors e.g. Enalapril and Captopril Oral side effects – angioedema, lichenoid reactions, loss of taste, erythema multiforme, burning mouth Avoid NSAIDs as risk of renal damage ACE inhibitors angioedema lichenoid reactions Blistering of mucous Cutaneous target-like membranes lesions  Calcium channel blockers e.g. Nifedipine and Diltiazem Oral side effects - gingival hyperplasia, headaches and flushing Gingival hyperplasia Flushing  Local anaesthesia and general anaesthesia  Reduce stress  Post-operative pain control  Drug interactions  Oral care