…and evidence based interventions. Many tachyarrhythmias carry a potential risk of serious morbidity or mortality, underscoring the need for a structured and guideline directed approach…

…impulse formation can cause arrhythmias by the following two mechanisms: Increased or abnormal automaticity Triggered activity Increased or abnormal automaticity As discussed in Chapter 1…

…coronary vasospasm, microvascular dysfunction, or combinations of these mechanisms. Drug selection can therefore be tailored to the suspected mechanism. No antianginal class has demonstrated consistent…

…mechanism is rupture or erosion of a vulnerable (unstable) atherosclerotic coronary plaque. Upon such damage, the plaque exposes highly thrombogenic materials which activate circulating platelets…

…activity is a central component of cardiovascular prevention and treatment. It is associated with lower cardiovascular and all cause mortality and with reduced incidence or…

…of these have atherosclerotic heart disease (coronary artery disease) as the underlying cause. Other common causes are cardiomyopathy (hypertrophic or dilated), arrhythmogenic right ventricular cardiomyopathy…

Arrhythmias and arrhythmology Pharmacology & dosing Definition and Pathophysiology Sotalol is a nonselective beta adrenoceptor blocker devoid of intrinsic sympathomimetic activity that also prolongs cardiac repolarization…

…consciousness. Urgent EEG if the patient does not wake or if ongoing electrographic seizure activity is suspected Benzodiazepines are the established first line treatment. Intravenous…

…crisis. Mechanism of action Phentolamine is a non selective alpha adrenergic blocker. Phentolamine reduces blood pressure while increasing catecholamine activity. Effects Primarily causes afterload reduction…

…atrium is activated passively. The upper boundary of this circuit may be located either anterior or posterior to the superior vena cava. A critical area…

…recreational or sporting activity Limit recurrent myocardial infarction, cardiovascular morbidity, and mortality The modern concept of rehabilitation has evolved from early post infarction physical activity…

…clearance of circulating LDL cholesterol (LDL C). Increased PCSK9 activity therefore contributes to higher LDL C concentrations. The genetic evidence provides the rationale for therapeutic…

…tachyarrhythmia, bradyarrhythmia or asystole. The tachyarrhythmias include ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The bradyarrhythmias include all bradyarrhythmias, pulse less electrical activity (PEA)…

…anaphylactic cardiac arrests present with pulseless electrical activity (PEA) as the initial rhythm, while the remainder manifest ventricular fibrillation (VF) or asystole ( Ebo et al…

…SA) node. This enhanced atrial activity is most commonly attributable to abnormal automaticity or re entry mechanisms; triggered activity is a less frequent cause. The…

…spontaneous cardiac rhythm. The likelihood of achieving spontaneous cardiac activity is a function of the duration of circulatory standstill and the underlying cause, as elaborated…

…electrical currents. An ECG lead is a graphical description of the electrical activity of the heart and it is created by analyzing several electrodes. In…

…with a meal or with continued glucose administration adapted to the cause. 8. Identify drugs, renal failure, alcohol, a missed meal, physical activity and any…

…atrial activity. The investigation is diagnostic, not therapeutic. An unstable patient should be cardioverted, not investigated. Contraindications Haemodynamic instability — hypotension, shock, impaired consciousness or pulmonary…

…Asystole with no electrical activity at all — pacing has no documented benefit there. Transcutaneous pacing: burns or wounds in the area where the pads would…

…The hypotensive effect of enalaprilat depends on plasma volume and plasma renin activity. Volume depletion and high plasma renin activity increase the effect of enalaprilat…

…organ hypoperfusion. In severe cases, bradycardia may progress to bradyarrhythmic arrest or pulseless electrical activity (PEA), presenting as cardiovascular collapse and cardiac arrest. Evaluation and…

…altering lipid concentrations, blood pressure or other conventional risk factors. Colchicine is an established anti inflammatory drug that may inhibit inflammasome activity, reduce interleukin 1…

…via the autonomic nervous system. It attenuates carotid sinus baroreceptor activity and acts centrally and peripherally to enhance vagal tone. These sympatho inhibitory effects decrease…

…vasodilation. Although primarily defined by these mechanisms, levosimendan also exhibits some type 3 phosphodiesterase inhibitor (PDEI) activity, which may contribute to its inotropic profile. The…

…at a particular symptom complex. The source material does not describe a characteristic symptom profile at initiation or during routine therapy. Potential clinically important complications…

…responses and immune activity. Statin intolerance refers to adverse effects attributed to statin treatment that improve or resolve after reducing the dose or stopping therapy…

…thrombus formation and sympathetic activation. Rho kinase may increase vascular smooth muscle sensitivity to calcium by inhibiting myosin phosphatase activity. Patients with VA are generally…

…subsequent ventricular activity (QRS) should result in pacing in the ventricles. To sense correctly, the pacemaker must detect near field depolarization currents (P or QRS…

…for a flat ETCO2 curve include: Ventilator or capnograph not activated. Displacement of the tracheal tube. Cardiac arrest without adequate blood flow or ineffective compressions…

…resulting in obstruction. Central nervous system (CNS) injuries might cause apnea or hypoventilation. Respiratory conditions : Tension pneumothorax Drowning Airway obstruction Hanging Pneumonia High altitude sickness…

…and can guide resuscitative efforts. If the patient presents with hypotension or has a lactate level exceeding 4 mmol/l, commence an intravenous fluid resuscitation…

…small to be detected by skin electrodes; the ECG presents the electrical activity of the atrial and ventricular myocardium. Automaticity of pacemaker cells The automaticity…

…contains the electronics, a battery , and one or two leads . The pulse generator generates the electric current needed to stimulate the myocardium. The current is…

…However, none of the ECG changes or arrhythmias are unique to digoxin. One should always suspect digoxin as the trigger of an arrhythmia (in patients…

…detail. Symptom during exercise stress testing Perceived exertion The patient's perceived exertion is a way of estimating the intensity of the physical activity. It…

…the myocardium). Thus, increased sympathetic activity results in increased heart rate and stronger contractions. Physical exercise increases the venous return to the heart, which results…

…to the assessment of exercise capacity. Metabolic equivalents (METs) can be used to estimate the energy cost of physical activity. One metabolic equivalent (1 MET…

…of ischemia or partial scarring. Severe defects : Defined by absent tracer uptake, with signal intensity comparable to background activity, typically representing infarcted tissue or non…

…These age variations in heart rate are due to variations in the activity of the autonomic nervous system and changes in the automaticity of the…

…be considered a basic clinical skill. Pacing activity may be visible or invisible, depending on e.g the type of pacemaker, intrinsic cardiac activity, etc…

Conduction defects ECG Left bundle branch block (LBBB) Left bundle branch block (LBBB) results from anatomical or functional impairment of the left bundle branch (LBB)…

…cause of pacemaker mediated tachycardia is endless loop tachycardia, which also depends on the ventricular stimulation being triggered by atrial activity. In endless loop tachycardia…

…vasodilators replicate the effects of exercise on coronary arteries, without the need for physical activity. Advantages of regadenoson over adenosine Regadenoson has advantages over adenosine…

…and high retention, with a linear relationship between myocardial blood flow and measured tracer activity over a wide range (Murthy et al.). As evident in…

…all ischemic episodes are asymptomatic (refer to The Ischemic Cascade). Acute coronary syndromes occur when atherosclerotic plaques rupture or erode, leading to atherothrombosis and occlusion…

…adequately increase its automaticity during physical activity). Sinus arrest & sinus pause (intermittent failures to discharge impulses). Sinoatrial block (delayed or blocked impulse conduction between the…

…of sinus tachycardia are as follows: Normal (physiologic) sinus tachycardia: The automaticity (rate of spontaneous depolarization) in the sinoatrial node is increased during physical activity…

…ventricular fibrillation) or cardioversion (ventricular tachycardia). Non shockable rhythm : Cardiac rhythm that cannot be defibrillated or cardioverted. These rhythms include pulse less electrical activity (PEA…

…Importantly, for the ventricles to have any electrical (and thus pumping) activity at all, an escape rhythm must arise in an ectopic focus (located distal…

…drug, dosing, route of administration and criteria for intermediate care or intensive care. Time course after the last intake The times given are approximate. Symptoms…

…Edema. Dizziness. Caution Should be used cautiously in patients with myocardial ischemia and/or heart failure. Nicardipine doses and administration in hypertension (hypertensive crisis/emergency)…

…including branch points in the epicardial coronary arteries. Early lesions may undergo positive or compensatory remodelling, in which the vessel enlarges outward before a major…

…atherosclerosis and premature myocardial infarction Coronary microvascular dysfunction Myocarditis and pericarditis Coronary or large vessel arteritis Pulmonary arterial vasculopathy and pulmonary hypertension Arterial and venous…

…adults with markedly limited physical activity. Traditional labels such as “typical” and “atypical” angina have limited value, particularly in patients with microvascular dysfunction or vasospasm…

…may progress to hemodynamic instability, presenting as shock or cardiac arrest manifesting as bradyarrhythmic arrest, asystole, or pulseless electrical activity (PEA). Evaluation and Physical Examination…

…Long term efficacy data remain limited, and the possibility that chronic If channel blockade could increase sympathetic activity, with adverse remodelling or pro arrhythmic c

…than 10% have classic claudication. Asymptomatic or atypical PAD remains clinically important. Reduced activity may lead to progressive functional decline, sedentary behaviour and loss of…

…Electromechanical dissociation or pulseless electrical activity despite ongoing sinus rhythm on the ECG. Subacute rupture may be suggested by: Nausea. Hypotension. Pericardial or pleuritic discomfort…

…resume and bradycardia should resolve with the onset of physical activity. Profound sinus bradycardia (<30 beats/min or sinus pauses ≥3 s) would warrant further…