Cardiovascular Emergencies

A good focused history is essential to the adequate assessment of chest pain. It is important to rapidly exclude potentially life-threatening causes of chest pain to avoid adverse clinical outcomes.This should be preceded by an ABCD (airway, breathing, circulation, disability) assessment. Once cardiac chest pain is determined to be likely, early risk stratification should be achieved in order to guide choice of further management.

Kawasaki's disease Structural lesions of coronary arteries: anomalous origin of left coronary artery from pulmonary artery; coronary artery ostial stenosis after neonatal arterial switch repair of D-transposition of great arteries Prothrombotic defects Physical examination in the presence of suspected cardiac chest pain includes: • Evaluation of haemodynamic status • Signs of sympathetic activation (pallor, sweating, tachycardia) or vagal activation (vomiting, bradycardia) • Signs of complications:pulmonary oedema, cardiogenic shock • Signs of non-coronary causes of acute chest pain: aortic dissection (asymmetrical pulses, differential blood pressure between left and right upper limbs, acute aortic regurgitation), pericarditis (pericardial friction rub) • Weight, height and calculation of body mass index, and waist circumference may help identify patients at risk of cardiac chest pain • Levine's sign of the use of the clenched fist to indicate the site of discomfort may indicate cardiac chest pain

Causes of acute chest pain Cardiovascular
a. Cardiac • Acute coronary syndromes: (ST elevation myocardial infarction (STEMI); non-ST elevation acute coronary syndrome (NSTE-ACS)): Angina is often described as crushing, heaviness, squeezing, aching, constricting or vice-like and can radiate to the back (mid-scapula), neck, jaw, and down one or both arms. The pain has a crescendo pattern and reaches a maximal intensity after a few minutes. Angina can be provoked by physical exertion, emo-tional stress and sexual intercourse, and aggravated by cold weather after heavy meals. Typically, angina is relieved following rest and/or administration of glyceryl trinitrate within around 5min. • Pericarditis: central or precordial pleuritic chest pain, worse when supine and relieved by sitting forward, and radiating to the trapezius ridge, neck, left shoulder and arm; pericardial rub on auscultation • Myocarditis (background of recent viral illness): pain may be related to myocardial ischaemia or concurrent pericarditis • Coronary vasospasm (cocaine; triptans) • Valvular heart disease (aortic stenosis; mitral valve prolapse) • Hypertrophic cardiomyopathy • Angina secondary to cardiac arrhythmia b. Aortic • Acute aortic syndromes: aortic dissection: abrupt onset of intense tearing or ripping retrosternal pain radiating to the back (inter-scapular region) and extending to the abdomen, hips and legs with distal extension, maximal at the onset; intramural haematoma; penetrating atherosclerotic ulcer; contained traumatic aortic rupture • Thoracic aortic aneurysm (ascending aortic aneurysms tend to cause anterior chest pain, arch aneurysms cause pain radiating to the neck, and descending thoracic aneurysms cause inter-scapular back pain) • Aortitis Congenital long QT syndromes (inherited ion channel disorders which predispose the ventricular myocardium to catecholamine-induced arrhythmias)

Chest x-ray features of pacemakers
With a single atrial lead visible on chest x-ray the pacing mode is almost certainly AAI® With a single ventricular lead, the mode is almost certainly VVI®, although dualchamber sensing from a single lead is now possible. This is termed VDI. If two leads are attached to the generator the system is dual-chamber, usually DDD®, with one lead in the right atrium and the other in the right ventricle.A biventricular pacemaker (cardiac resynchronization therapy device) has one lead in the right ventricle and one in the left ventricle.

Characteristics of the pacemaker inpulse
Sharp, narrow, vertically oriented spike less than 2 ms in duration If it appears before a P wave, it is pacing the atrium If it appears before the QRS complex, it is pacing the ventricle The QRS complex that follows a pacing spike resembles a LBBB pattern, due to right ventricular stimulation. There may also be changes in T wave morphology, eg T wave inversion and QT prolongation

Pacemaker problems
A. Failure to pace: no pacing spikes, when there should be For one or both chambers, either no pacing artefacts will be present on the ECG, or artefacts will be present for one but not the other chamber.

Heart failure
Acute heart failure has been defined as "a change in heart failure signs and symptoms resulting in the need for urgent therapy" The patient in acute heart failure can be categorised on the basis of haemodynamic profiles as warm + wet, cold + wet, cold + dry or warm + dry, as defined by peripheral perfusion (warm/ cold) and lung auscultation (wet/dry) European society of cardiology classification of acute heart failure syndromes • Acute decompensated heart failure (de novo or decompensated chronic heart failure) • Hypertensive acute heart failure • Acute heart failure with pulmonary oedema • Cardiogenic shock • High output heart failure Presenting symptoms and signs of heart failure include • Breathlessness; exercise intolerance; orthopnoea; paroxysmal nocturnal dyspnoea • Raised jugular venous pressure, peripheral oedema (ankles, sacrum, genitalia); gallop rhythm (S3); lateral displacement of the apex beat; bilateral crackles in the lungs; hepatomegaly; ascites; gain in body weight • A single measurement in the untreated patient of BNP (B-type natriuretic peptide) <100 ng/L or NT-proBNP (N-terminal pro-BNP) <300 ng/L makes the diagnosis of heart failure unlikely New York Heart Association Classification of Heart Failure (functional characterisation of patients with chronic heart failure) Class I No limitation: ordinary physical exercise does not cause fatigue, dyspnoea or palpitations Class II Slight limitation of physical activity: comfortable at rest but ordinary activity results in fatigue, palpitations, dyspnoea or angina Class III Marked limitation of physical activity: comfortable at rest but less than ordinary activity results in symptoms Class IV Unable to carry out any physical activity without discomfort: symptoms of heart failure are present even at rest with increased discomfort with any physical activity

Features of pericardial effusion on bedside ultrasound
• Anechoic pericardial space, separating the bright white highly echogenic parietal pericardium from the heterogeneous grey myocardium.
• A volume greater than 100 ml leads to circumferential fluid filling the entire pericardial space, thereby circumscribing the entire heart • The collection is larger posterior to the left heart than anterior to the right heart in supine patients • A haemodynamically significant pericardial effusion causes right ventricular diastolic collapse -persistent inward of the right ventricular free wall during diastole; right atrial systolic collapse; a dilated noncollapsible inferior vena cava without partial collapse with inspiration; and inter-ventricular septal flattening

Features of postural orthostatic tachycardia syndrome
• An increase in heart rate by at least 30 beats per minute or to greater than 120 beats per minute within the first 10 min of assuming an upright posture, with no associated drop in blood pressure. • Symptoms of postural intolerance can be cardiac (palpitations, chest discomfort, dyspnoea, presyncope or syncope, effort intolerance) or non-cardiac (nausea, lightheadedness, blurred vision, tremulousness, weakness) • There may be evidence of dependent acrocyanosis (red-blue discolouration of the legs) with prolonged standing