MED405 — Cardiology I: Lecture Note

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This is the complete lecture note for MED405 Cardiology I. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.

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Course code: MED 405 Course title: Cardiology I Course credit load: 2 Units Series 1: Evaluation of the Cardiac Patient and Common Cardiovascular Symptoms • Part 1.1: Approach to the Cardiac Patient o Sub Part 1.1.1: Overview of cardiac history taking o Sub Part 1.1.2: Cardiovascular risk factor assessment o Sub Part 1.1.3: Functional classification of cardiac symptoms • Part 1.2: Chest Pain o Sub Part 1.2.1: Characteristics of cardiac chest pain o Sub Part 1.2.2: Differential diagnosis of chest pain o Sub Part 1.2.3: Clinical approach to the patient with chest pain • Part 1.3: Dyspnoea, Orthopnoea, and Paroxysmal Nocturnal Dyspnoea o Sub Part 1.3.1: Dyspnoea of cardiac origin o Sub Part 1.3.2: Orthopnoea and its mechanism o Sub Part 1.3.3: Paroxysmal nocturnal dyspnoea • Part 1.4: Palpitations and Other Cardiovascular Symptoms o Sub Part 1.4.1: Palpitations: definition, causes, and assessment o Sub Part 1.4.2: Syncope and presyncope

o Sub Part 1.4.3: Oedema and other peripheral symptoms Introduction Cardiovascular disease is the leading cause of death globally and a major and growing burden in Nigeria. The foundation of accurate cardiovascular diagnosis is a systematic, thorough clinical assessment: a carefully taken history identifies the nature and severity of symptoms, establishes risk factors, and guides the clinician's thinking before any investigation is ordered. This Series introduces the structured approach to evaluating the cardiac patient, covering the systematic cardiovascular history, risk factor assessment, and functional classification of cardiac symptoms. It then examines the four cardinal cardiovascular symptoms in detail: chest pain, dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea, and palpitations, with additional coverage of syncope, presyncope, and peripheral oedema. Mastery of symptom recognition and systematic history taking is the essential first step in cardiology, enabling the clinician to generate a focused differential diagnosis and select appropriate investigations without unnecessary testing. Series Learning Outcomes Upon completing this Series, you should be able to: • SLO 1.1 describe the structured approach to cardiovascular history taking and risk factor assessment (Linked to Part 1.1), • SLO 1.2 explain the NYHA functional classification of cardiac symptoms (Linked to Part 1.1), • SLO 1.3 describe the characteristics of cardiac chest pain, its differential diagnosis, and the clinical approach to the patient presenting with chest pain (Linked to Part 1.2),

• SLO 1.4 describe the mechanisms and clinical features of dyspnoea, orthopnoea, and paroxysmal nocturnal dyspnoea of cardiac origin (Linked to Part 1.3), and • SLO 1.5 describe the causes and clinical assessment of palpitations, syncope, and peripheral oedema in the cardiac patient (Linked to Part 1.4). 1.1 Approach to the Cardiac Patient 1.1.1 Overview of cardiac history taking The cardiovascular history follows the standard medical history structure but with specific emphasis on the cardinal cardiovascular symptoms: chest pain, dyspnoea (including orthopnoea and paroxysmal nocturnal dyspnoea), palpitations, syncope, and peripheral oedema. Each symptom is explored using the SOCRATES framework (Site, Onset, Character, Radiation, Associations, Timing, Exacerbating and relieving factors, Severity) to characterise it fully. In addition to the presenting complaint, the cardiac history must document past medical history of cardiovascular disease (previous myocardial infarction, angina, heart failure, rheumatic fever, hypertension, stroke), drug history including all prescribed and over-the-counter medications with attention to cardiotoxic agents, and family history of premature cardiovascular disease, sudden cardiac death, or inherited conditions such as hypertrophic cardiomyopathy. Fill in the blank: The cardiovascular history explores the cardinal symptoms (chest pain, dyspnoea, palpitations, syncope, oedema), past medical history of cardiac disease, drug history for cardiotoxic agents, and ________ history of premature cardiovascular disease. 1.1.2 Cardiovascular risk factor assessment Cardiovascular risk factors are conditions and behaviours that increase the probability of developing cardiovascular disease. They are classified as modifiable (hypertension, dyslipidaemia, diabetes mellitus, smoking, obesity, physical inactivity, excessive alcohol) and

non-modifiable (age, male sex, family history of premature cardiovascular disease, and in women, early menopause). In clinical practice, risk factor assessment is used to calculate a patient's global cardiovascular risk using tools such as the Framingham Risk Score or the WHO cardiovascular risk prediction charts adapted for Africa. High global risk (above 20 percent 10-year risk of a major cardiovascular event) justifies aggressive risk factor modification regardless of the presence of symptoms. In Nigeria, hypertension, diabetes, and obesity are the most prevalent modifiable cardiovascular risk factors. Fill in the blank: Cardiovascular risk factors are modifiable (hypertension, dyslipidaemia, diabetes, smoking, obesity) or non-modifiable (age, sex, family history); global risk is estimated using tools such as the ________ Risk Score. 1.1.3 Functional classification of cardiac symptoms The New York Heart Association (NYHA) functional classification is the most widely used system for grading the severity of cardiac symptoms in relation to functional capacity. It comprises four classes: Class I: no limitation of ordinary physical activity; ordinary activity does not cause symptoms. Class II: slight limitation; comfortable at rest but ordinary activity causes symptoms. Class III: marked limitation; comfortable at rest but less than ordinary activity causes symptoms. Class IV: symptoms at rest; any activity causes discomfort. Fill in the blank: The NYHA functional classification grades cardiac symptoms from Class I (no limitation of ordinary activity) to Class IV (symptoms at ________) and is used to assess symptom severity and monitor treatment response.

Figure 1.1: Components of the cardiovascular history and classification of cardiovascular risk factors Pilot questions 1.1 1. Describe the components of a comprehensive cardiovascular history. (Linked to SLO 1.1) 2. Distinguish between modifiable and non-modifiable cardiovascular risk factors with examples of each. (Linked to SLO 1.1) 3. Explain what global cardiovascular risk means and how it is estimated. (Linked to SLO 1.1) 4. State and define the four NYHA functional classes. (Linked to SLO 1.2) 5. Explain how the NYHA classification is used in clinical practice. (Linked to SLO 1.2) 1.2 Chest Pain

1.2.1 Characteristics of cardiac chest pain Cardiac chest pain most commonly arises from myocardial ischaemia and has characteristic features that distinguish it from non-cardiac causes. Classic ischaemic chest pain (angina pectoris) is typically described as a tight, heavy, pressing, or crushing discomfort (rather than a sharp or stabbing pain) in the central chest or retrosternal area, radiating to the left arm, jaw, neck, or back, precipitated by exertion or emotion, relieved by rest and glyceryl trinitrate within minutes, and lasting from 2 to 15 minutes. Acute myocardial infarction (AMI) produces a similar but more severe and prolonged pain, typically lasting more than 20 minutes, not relieved by glyceryl trinitrate, and accompanied by diaphoresis, nausea, vomiting, and autonomic features. Pericarditis causes sharp, pleuritic chest pain (worse on inspiration and lying flat, relieved by sitting forward). Aortic dissection presents with severe, tearing pain radiating to the back, reaching maximum intensity at onset. Fill in the blank: Classic ischaemic chest pain is central, tight or crushing, radiating to the left arm or jaw, precipitated by exertion, and relieved by rest or glyceryl trinitrate within minutes; pain lasting more than 20 minutes not relieved by GTN suggests acute ________ infarction. 1.2.2 Differential diagnosis of chest pain The differential diagnosis of chest pain is broad and includes both cardiac and non-cardiac causes. Cardiac causes include stable angina (predictable exertional pain relieved by rest), unstable angina and NSTEMI (anginal pain at rest or with minimal exertion, representing acute coronary syndrome), STEMI (severe prolonged ischaemic pain with ST elevation), pericarditis, and aortic dissection. Non-cardiac causes include pulmonary embolism (pleuritic pain with dyspnoea and haemoptysis), pneumothorax (sudden-onset pleuritic pain with dyspnoea), pneumonia and pleuritis (pleuritic pain with fever and cough), oesophageal disease (burning retrosternal pain related to food, relieved by antacids), musculoskeletal pain (localised, reproducible on palpation), and anxiety and panic disorder (often sharp, atypical, associated with autonomic features).

Fill in the blank: Cardiac causes of chest pain include stable angina, unstable angina and NSTEMI, STEMI, pericarditis, and aortic dissection; non-cardiac causes include pulmonary embolism, pneumothorax, ________ disease, and musculoskeletal pain. 1.2.3 Clinical approach to the patient with chest pain The clinical approach to chest pain prioritises identifying life-threatening causes (AMI, aortic dissection, pulmonary embolism, tension pneumothorax) that require immediate management before full diagnostic evaluation. A rapid assessment includes the nature and duration of pain, associated symptoms (dyspnoea, diaphoresis, haemoptysis, syncope), vital signs, and an ECG within 10 minutes of presentation in any patient with possible acute coronary syndrome. Initial investigations include 12-lead ECG (ST elevation, depression, or T-wave changes), cardiac troponin (elevated in myocardial injury; serial measurement at 0 and 3 hours), chest X-ray (mediastinal widening in aortic dissection; pneumothorax; pulmonary oedema), and oxygen saturation. The history remains the most important component of the assessment; features that increase probability of a cardiac cause include typical pain character, age and sex, presence of multiple risk factors, and a prior history of coronary artery disease. Fill in the blank: Chest pain assessment prioritises life-threatening causes; initial investigations include ECG within 10 minutes, serial cardiac ________, chest X-ray, and oxygen saturation; the history remains the most important assessment component. Cardiac Causes Non-Cardiac Causes Stable Angina – exertional pain, relieved by rest or nitroglycerin Pulmonary Embolism – sudden pleuritic pain, dyspnoea, risk factors for thrombosis Unstable Angina/NSTEMI – pain at rest, prolonged, ECG changes without ST elevation

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