Difficulty: Beginner to Intermediate | Prerequisites: Parts 1 and 2 of this series; familiarity with basic cardiac and cerebrovascular conditions.
Once you understand the conditions (Parts 1 and 2), the next question is: how do clinicians detect them, treat them, and what symptoms do patients actually present with? This section covers the diagnostic imaging and electrical tests used to evaluate the heart and brain, the medications and procedures used to treat cardiovascular problems, and the clinical signs and symptoms that point toward underlying disease. These terms appear heavily in exam questions that give you a clinical scenario and ask you to identify the correct test, treatment, or diagnosis.
Doctors look at the heart and vessels using ultrasound (echocardiography, Doppler), electrical tracings (ECG, EEG), and imaging (CT, cineangiography). They treat problems with drugs (digitalis, diuretics), devices (defibrillators), and procedures (commissurotomy, cryoablation). Patients present with symptoms like leg pain on walking (claudication), shortness of breath (dyspnoea), slurred speech (dysarthria), and blood clots in the legs (DVT). Match the symptom to the condition to the test to the treatment, and you have the clinical reasoning chain exams love to test.
Cineangiography
A diagnostic imaging technique that uses X-rays and contrast dye to produce moving images of blood flow through the heart and blood vessels. It allows clinicians to visualise blockages, narrowing, and abnormal flow patterns in real time.
Think of it as a live video X-ray of your blood vessels. The "cine" prefix refers to motion (as in cinema). Particularly useful for identifying coronary artery blockages before deciding on bypass surgery or stenting.
Tags: cineangiography, angiography, cardiac catheterisation, X-ray blood vessel imaging, contrast dye imaging
CT Scan (Computed Tomography)
An imaging technique that uses multiple X-ray beams taken from different angles, processed by a computer to produce detailed cross-sectional images of the body.
In simple terms, it is a far more detailed X-ray that slices through the body in layers, like cutting a loaf of bread. In cardiovascular and cerebrovascular medicine, CT scans are used to detect brain bleeds (haemorrhagic stroke), brain tissue damage, and heart abnormalities. A CT angiogram adds contrast dye to visualise blood vessels.
Tags: CT scan, computed tomography, CAT scan, cross-sectional imaging, brain scan, CT angiogram
Doppler Ultrasound
A non-invasive test that uses high-frequency sound waves to measure the speed and direction of blood flow through vessels.
Think of it as: the same principle that makes a siren sound higher-pitched as an ambulance approaches. Sound waves bounce off moving blood cells, and the frequency shift tells clinicians how fast and in which direction blood is flowing. Used to detect blood clots (DVT), blocked or narrowed arteries, and venous insufficiency.
Tags: Doppler ultrasound, Doppler sonography, blood flow test, vascular ultrasound, DVT detection
Echocardiography
An ultrasound of the heart. It uses sound waves to create real-time images of the heart's chambers, valves, walls, and blood flow patterns.
In simple terms, it is the heart's equivalent of the ultrasound scan used during pregnancy, only pointed at the chest. Echocardiography is the primary tool for measuring ejection fraction, assessing valve function, and detecting structural abnormalities. It is non-invasive, involves no radiation, and can be performed at the bedside.
Tags: echocardiography, echo, cardiac ultrasound, heart ultrasound, transthoracic echocardiogram, TTE
Electrocardiogram (ECG or EKG)
A test that records the electrical activity of the heart over time using electrodes placed on the skin. The resulting trace shows the timing and strength of each phase of the heartbeat.
Think of it as a printout of the heart's electrical wiring in action. Each wave on the trace (P wave, QRS complex, T wave) corresponds to a specific event in the conduction system. ECGs detect arrhythmias, heart attacks (ST-segment changes), and conduction abnormalities. The abbreviation EKG comes from the German spelling, Elektrokardiogramm.
Tags: ECG, EKG, electrocardiogram, heart tracing, cardiac electrical test, P wave, QRS complex, arrhythmia detection
Electroencephalogram (EEG)
A test that records electrical activity in the brain using electrodes placed on the scalp.
In simple terms, it is the brain's equivalent of an ECG. EEGs are used to diagnose epilepsy, sleep disorders, and to assess brain function after a stroke or head injury. In the context of CVA-related terms, an EEG may be used to evaluate the extent of brain damage following a stroke.
Tags: EEG, electroencephalogram, brain wave test, brain electrical activity, epilepsy diagnosis
Commissurotomy
A surgical procedure to open a heart valve that has become narrowed (stenotic). The surgeon cuts through the fused or thickened valve tissue to widen the opening and restore normal blood flow.
Think of it as: the valve leaflets have stuck together, and the surgeon carefully cuts them apart. Most commonly performed on the mitral valve (mitral commissurotomy). It can be done as open-heart surgery or via a balloon catheter (balloon valvuloplasty).
Tags: commissurotomy, valve surgery, mitral commissurotomy, valve stenosis repair, valvulotomy
Cryoablation
A procedure that uses extreme cold (typically liquid nitrous oxide or argon gas delivered through a catheter) to destroy small areas of heart tissue that are causing abnormal electrical signals.
In simple terms, the cardiologist freezes the bit of heart tissue that is misfiring. This is used to treat arrhythmias, particularly atrial fibrillation and supraventricular tachycardia. The frozen tissue forms a scar that can no longer conduct the faulty electrical impulses.
Tags: cryoablation, cardiac ablation, freeze ablation, arrhythmia treatment, atrial fibrillation ablation
Defibrillator
A device that delivers a controlled electrical shock to the heart to restore a normal rhythm during life-threatening arrhythmias such as ventricular fibrillation or pulseless ventricular tachycardia.
Think of it as: the heart's electrical system has descended into chaos, and the shock resets it. External defibrillators (AEDs) are found in public places. Implantable cardioverter-defibrillators (ICDs) are surgically placed in patients at high risk of sudden cardiac arrest.
Tags: defibrillator, AED, automated external defibrillator, ICD, implantable cardioverter-defibrillator, cardiac arrest treatment, electrical cardioversion
Digitalis
A class of medication derived from the foxglove plant, used to strengthen heart muscle contractions and slow the heart rate. The most common form is digoxin.
In simple terms, digitalis makes the heart beat more strongly and more slowly. It is prescribed for congestive heart failure (to improve pump output) and for certain arrhythmias such as atrial fibrillation (to control the heart rate). Digitalis has a narrow therapeutic window, meaning the difference between an effective dose and a toxic dose is small.
Tags: digitalis, digoxin, cardiac glycoside, foxglove, heart failure medication, positive inotrope
Diuretic
A medication that increases urine production, helping the body eliminate excess fluid and sodium. Commonly called "water pills."
Think of it as: the body is holding onto too much fluid (oedema, pulmonary congestion), and diuretics tell the kidneys to flush it out. Used in heart failure, hypertension, and oedema management. Common types include loop diuretics (furosemide), thiazides (hydrochlorothiazide), and potassium-sparing diuretics (spironolactone).
Tags: diuretic, water pill, furosemide, Lasix, thiazide, fluid management, oedema treatment, blood pressure medication
Claudication
Pain, cramping, or fatigue in the legs (typically the calves) that occurs during walking or exercise and is relieved by rest. It is caused by insufficient blood flow to the leg muscles, usually due to peripheral artery disease (PAD).
In simple terms, the leg muscles are not getting enough blood when they are working hard, so they cramp up. The pattern of "walk, pain, stop, relief" is the hallmark. Intermittent claudication is an early warning sign of widespread atherosclerosis.
Tags: claudication, intermittent claudication, leg pain on walking, peripheral artery disease, PAD, leg cramps, poor circulation
Deep Vein Thrombosis (DVT)
A blood clot that forms in a deep vein, most commonly in the legs. The danger is that the clot can break loose (embolise) and travel to the lungs, causing a pulmonary embolism (PE).
Think of it as: a clot forms in the deep plumbing of the leg, and if it dislodges, it can block blood flow in the lungs, which is potentially fatal. Risk factors include prolonged immobility (long flights, bed rest after surgery), recent surgery, pregnancy, and clotting disorders. Symptoms include leg swelling, warmth, redness, and pain.
Tags: DVT, deep vein thrombosis, leg clot, venous thromboembolism, VTE, pulmonary embolism risk, blood clot in leg
Dysarthria
Difficulty speaking caused by weakness or poor coordination of the muscles used for speech (tongue, lips, jaw, vocal cords). The person knows what they want to say but cannot form the words clearly.
In simple terms, the speech muscles are not working properly. Dysarthria is a common symptom of stroke (CVA), particularly when the brainstem or motor cortex is affected. It is distinct from aphasia, which is a language disorder (difficulty finding or understanding words rather than difficulty physically producing them).
Tags: dysarthria, slurred speech, speech muscle weakness, stroke symptom, motor speech disorder, dysarthria vs aphasia
Dyspnoea
Difficulty breathing or shortness of breath. It is a subjective sensation that can range from mild breathlessness on exertion to severe air hunger at rest.
Think of it as: the feeling that you cannot get enough air. In cardiovascular disease, dyspnoea often signals left-sided heart failure (fluid backing up into the lungs) or severe anaemia (not enough oxygen-carrying capacity). Paroxysmal nocturnal dyspnoea (PND) is a classic heart failure symptom where the patient wakes up gasping for air at night.
Tags: dyspnoea, dyspnea, shortness of breath, SOB, breathlessness, PND, paroxysmal nocturnal dyspnoea, heart failure symptom
ECG/EKG: First-line test for any suspected cardiac electrical problem. Quick, cheap, non-invasive. Detects arrhythmias, heart attacks (ST elevation or depression), and conduction blocks.
Echocardiography: First-line test for assessing heart structure and function. Measures ejection fraction, evaluates valves, and detects structural defects. No radiation.
Doppler ultrasound: The go-to for suspected blood clots (DVT) or arterial blockages in the limbs. Non-invasive, no radiation.
CT scan: Used in acute settings to distinguish ischaemic stroke from haemorrhagic stroke (critical because the treatments are opposite). Also used to image the heart and great vessels.
Cineangiography: A more invasive test reserved for when clinicians need to see coronary arteries in detail, usually before planning bypass surgery or stenting. Requires catheterisation and contrast dye.
EEG: Records brain electrical activity. Used after stroke to assess brain function, and in epilepsy diagnosis. Not a cardiac test but included in CVA-related terminology because strokes affect the brain.
Digitalis (digoxin): Strengthens heart contractions (positive inotrope) and slows heart rate. Used in CHF and atrial fibrillation. Watch for toxicity: nausea, visual disturbances (yellow-green halos), arrhythmias.
Diuretics: Remove excess fluid. Essential in managing CHF and hypertension. Monitor potassium levels, especially with loop diuretics, as they can cause hypokalaemia.
Defibrillators: Reset the heart's electrical rhythm during life-threatening arrhythmias. AEDs are designed for use by non-medical bystanders. ICDs are implanted in high-risk patients.
Cryoablation: Targeted destruction of tissue causing arrhythmias. An alternative to radiofrequency ablation. Used when medication alone does not control the rhythm.
Commissurotomy: Mechanical widening of a stenotic valve. Less common now that catheter-based techniques (balloon valvuloplasty) and valve replacement surgery have advanced, but the term still appears in exams.
Claudication: Leg pain on exertion, relieved by rest. Points to peripheral artery disease and, by extension, systemic atherosclerosis. If a patient has claudication, their coronary and cerebral arteries may be narrowed as well.
DVT: A clot in a deep leg vein. The immediate danger is not the leg pain but the possibility of a pulmonary embolism if the clot breaks free.
Dysarthria: Slurred speech from weak speech muscles. A stroke symptom. Do not confuse with aphasia (a language processing problem).
Dyspnoea: Shortness of breath. In a cardiovascular context, think left-sided heart failure first. Paroxysmal nocturnal dyspnoea (waking at night unable to breathe) is a classic exam clue for CHF.
The ECG is one of the most widely performed medical tests in the world. Paramedics run a 12-lead ECG in the ambulance to detect a heart attack in progress, allowing the hospital to prepare the catheterisation lab before the patient arrives. AEDs in airports, shopping centres, and sports venues have saved thousands of lives by allowing bystanders to defibrillate a patient in cardiac arrest before emergency services arrive. Doppler ultrasound screening in post-surgical patients has significantly reduced deaths from undetected DVT and subsequent pulmonary embolism.
Students often confuse dysarthria with aphasia. Dysarthria is a motor problem (the muscles that produce speech are weak or uncoordinated). Aphasia is a language problem (the brain's language centres are damaged, affecting the ability to find, form, or understand words). A stroke patient can have both.
"Dyspnoea" is sometimes mistakenly equated with asthma. Dyspnoea is a symptom (shortness of breath), not a diagnosis. It can result from heart failure, lung disease, anaemia, anxiety, or many other causes.
Defibrillation and cardioversion are related but not identical. Defibrillation delivers an unsynchronised shock for cardiac arrest rhythms (ventricular fibrillation). Cardioversion delivers a synchronised shock for organised but abnormal rhythms (e.g. atrial fibrillation with a pulse).
Students sometimes assume diuretics treat the heart directly. They do not. Diuretics reduce the volume of fluid the heart has to pump, which reduces the workload on a failing heart. The benefit is indirect.
⚠️ Know which test to order for which scenario. ECG for electrical problems, echocardiography for structural/functional assessment, CT for acute stroke differentiation, Doppler for suspected DVT.
⚠️ Digitalis toxicity is a classic exam topic. Know the signs: nausea, visual changes (yellow-green halos), and new arrhythmias in a patient already on digoxin.
⚠️ The DVT-to-PE pathway is heavily tested. A clot forms in a deep leg vein, breaks free, travels through the right side of the heart, and lodges in the pulmonary arteries.
⚠️ Distinguish dysarthria from aphasia. Exams frequently present a stroke patient and ask you to classify the speech difficulty.
⚠️ Paroxysmal nocturnal dyspnoea (PND) is a classic exam clue for left-sided heart failure.
Q: True or false: An ECG uses sound waves to image the heart.
A: False. An ECG records electrical activity using electrodes. Echocardiography uses sound waves.
Q: Fill in the blank: A blood clot in a deep leg vein is called ________.
A: Deep vein thrombosis (DVT).
Q: True or false: Dysarthria is a problem with understanding language.
A: False. Dysarthria is a motor speech problem (difficulty forming words). Aphasia is the language comprehension/production problem.
Q: What class of medication reduces fluid overload in heart failure by increasing urine output?
A: Diuretics.
Q: True or false: A defibrillator is used to start a heart that has completely stopped.
A: False. A defibrillator resets a heart that is in a chaotic electrical rhythm (e.g. ventricular fibrillation). It does not restart a heart in asystole (flatline).
Q: A post-surgical patient develops sudden leg swelling, warmth, and pain in the left calf. What condition should be suspected, and what test would confirm it?
A: Deep vein thrombosis (DVT). A Doppler ultrasound of the leg veins would confirm the diagnosis by detecting the clot and assessing blood flow.
Q: A patient with atrial fibrillation is being treated with digoxin. They report nausea, blurred vision, and seeing yellow-green halos. What is the likely problem?
A: Digitalis (digoxin) toxicity. Digoxin has a narrow therapeutic window, and these symptoms (nausea, visual disturbances, particularly yellow-green halos) are classic signs that the drug level has become toxic.
Q: Explain the difference between an ECG and an echocardiogram. When would you use each?
A: An ECG records the heart's electrical activity and is used to detect arrhythmias, heart attacks, and conduction abnormalities. An echocardiogram uses ultrasound to image the heart's structure and is used to assess valve function, ejection fraction, and structural defects. ECG for electrical questions, echo for structural/functional questions.
Q: A patient experiences leg cramps and pain in the calves when walking that resolves with rest. What is this symptom called, and what does it suggest about the patient's vascular health?
A: Intermittent claudication. It suggests peripheral artery disease (atherosclerosis in the leg arteries) and indicates that the patient likely has systemic atherosclerosis affecting other vascular beds (coronary, cerebral) as well.
Q: What is cryoablation, and what type of cardiac condition is it used to treat?
A: Cryoablation is a procedure that uses extreme cold to destroy small areas of heart tissue responsible for generating abnormal electrical signals. It is used to treat arrhythmias such as atrial fibrillation and supraventricular tachycardia.
ECG interpretation connects to the conduction system material in Part 2: each wave on the ECG trace maps to a specific step in the SA node → AV node → bundle of His → Purkinje fibres pathway. DVT and pulmonary embolism link to the respiratory system unit (gas exchange, ventilation-perfusion mismatch). Diuretics and fluid balance connect to renal physiology (nephron function, electrolyte regulation). Dysarthria and aphasia tie into the neuroanatomy of speech (Broca's area, motor cortex, cranial nerves).
cineangiography, angiography, CT scan, computed tomography, Doppler ultrasound, echocardiography, echo, ECG, EKG, electrocardiogram, EEG, electroencephalogram, commissurotomy, cryoablation, cardiac ablation, defibrillator, AED, ICD, digitalis, digoxin, diuretic, water pill, furosemide, claudication, intermittent claudication, peripheral artery disease, PAD, deep vein thrombosis, DVT, pulmonary embolism, PE, dysarthria, slurred speech, aphasia, dyspnoea, shortness of breath, PND, paroxysmal nocturnal dyspnoea, cardiac imaging, heart failure treatment, arrhythmia treatment, stroke symptoms