CARDIOLOGY REVISION
ECG
- Rate: divide number of big squares between two consecutive R waves
- Rhythm:
- Regularly irregular - sinus arrhythmia, atrial flutter
- Irregularly irregular - atrial fibrillation, atrial flutter, 2nd degree heart block
- Axis: I and II positive is normal, I positive and II negative is left axis deviation (leaving), I
negative and III (± II) positive is right axis deviation (returning)
- P wave: precedes each QRS complex, upright in II, III and aVF, inverted in aVR
- Absent - atrial fibrillation, hyperkalaemia
- Bifid - P mitrale (indicates left atrial hypertrophy, mitral stenosis)
- Peaked - P pulmonale (indicates right atrial hypertrophy, pulmonary hypertension)
- PR interval: 3-5 small squares (0.12-0.2s)
- Shortened (faster AV conduction) - Wolff-Parkinson-White syndrome
- Prolonged (slower AV conduction) - 1st degree heart block, hypokalaemia
- QRS complex: <3 small squares (<0.2s)
- Shortened (supraventricular origin)
- Prolonged (ventricular origin or aberrant conduction of supraventricular
complexes) - bundle branch block, hyperkalaemia
- Peaked - ventricular hypertrophy
- Pathological Q waves - within a few days of an MI
- QT interval:
- Shortened - hypercalcaemia
- Prolonged - hypokalaemia, hypocalcaemia, hypothermia, antiarrhythmics
(amiodarone, flecainide), antimicrobials (erythromycin, clarithromycin,
fluconazole, ketoconazole), antipsychotics, antidepressants, antiemetics
- ST segment: isoelectric
- Elevated - normal variant (high take-off), STEMI, vasospastic/variant/Prinzmetal
angina, acute pericarditis (saddle-shaped)
- Depressed - normal variant (upward sloping), NSTEMI, posterior MI (V1-V3),
unstable angina, digoxin effect (downward sloping)
- T wave: inverted in aVR and sometimes aVL, III, V1, V2 and V3
- Abnormal if inverted in I, II, aVF, V4-6
- Inverted in V5 and V6 - digoxin effect (reversed tick)
- Peaked - hyperkalaemia, TCA overdose, within a few hours of an MI
- Flattened - hypokalaemia, hypocalcaemia, within 24 hours of an MI
- Other waves:
- J wave - hypothermia
- U wave - hypokalaemia
- Delta wave - Wolff-Parkinson-White syndrome
Hyperkalaemia - tall tented T waves, prolonged QRS complex, absent P waves, ‘sine wave’
pattern
Hypokalaemia - “In hypokalaemia U have no Pot and no Tea, but a long PR and a long QT”
, I Lateral aVR V1 Septal/anterior V4 Anterior
Left circumflex artery LAD LAD
II Inferior aVL V2 Septal/anterior V5 Lateral
RCA LAD Left circumflex artery
III Inferior aVF Inferior V3 Anterior V6 Lateral
RCA RCA LAD Left circumflex artery
- SAN - RCA in 60%, left circumflex artery in 40% (sinoatrial node branch)
- AVN - RCA in 80%, left circumflex artery in 20% (atrioventricular node branch)
ANGINA
- Constricting discomfort in the chest, neck, shoulders, jaw or arms caused by an insufficient
blood supply to the heart
- #1 coronary artery disease (other causes include valvular heart disease (aortic
stenosis), HOCM, hypertension)
- Stable angina - occurs with exertion or stress, relieved by rest or GTN within 5m
- Unstable angina - occurs at rest, new onset or abrupt deterioration of stable
angina, follow ‘NSTEMI and unstable angina’ tx
- Vasospastic/variant/Prinzmetal angina - due to coronary artery spasm,
ECG during pain shows ST elevation
- Canadian Cardiovascular Society grading
- Class I - sx on strenuous exertion
- Class II - sx on moderate exertion
- Class III - sx on mild exertion
- Class IV - sx at rest
- Dx: full hx, bedside (BP, ECG), bloods (for conditions which exacerbate)
- Tx: assess QRISK score (>10% consider primary prevention dose statin)
- Acute - sublingual GTN
- Chronic - #1 BB or CCB then increase dose then BB + CCB
- #2 long-acting nitrate, nicorandil, ivabradine, ranolazine
- Remember if CCB monotherapy use non-dihydropyridine rate-limiting CCB
(verapamil or diltiazem) and if dual-therapy use dihydropyridine (nifedipine)
- Tolerance can develop to (standard release) isosorbide mononitrate, if
tolerance develops then take 2nd dose at 8h not 12h to maintain
concentrations
ACUTE CORONARY SYNDROMES (ACS)
- STEMI and NSTEMI have troponin rise due to (mainly LV) myocardial cell death, unstable
angina does not
- But also raised in any cause of LV dysfunction, interventions which ‘damage’ the
heart (CPR, defibrillation, cardioversion, ablation) and renal failure
ECG
- Rate: divide number of big squares between two consecutive R waves
- Rhythm:
- Regularly irregular - sinus arrhythmia, atrial flutter
- Irregularly irregular - atrial fibrillation, atrial flutter, 2nd degree heart block
- Axis: I and II positive is normal, I positive and II negative is left axis deviation (leaving), I
negative and III (± II) positive is right axis deviation (returning)
- P wave: precedes each QRS complex, upright in II, III and aVF, inverted in aVR
- Absent - atrial fibrillation, hyperkalaemia
- Bifid - P mitrale (indicates left atrial hypertrophy, mitral stenosis)
- Peaked - P pulmonale (indicates right atrial hypertrophy, pulmonary hypertension)
- PR interval: 3-5 small squares (0.12-0.2s)
- Shortened (faster AV conduction) - Wolff-Parkinson-White syndrome
- Prolonged (slower AV conduction) - 1st degree heart block, hypokalaemia
- QRS complex: <3 small squares (<0.2s)
- Shortened (supraventricular origin)
- Prolonged (ventricular origin or aberrant conduction of supraventricular
complexes) - bundle branch block, hyperkalaemia
- Peaked - ventricular hypertrophy
- Pathological Q waves - within a few days of an MI
- QT interval:
- Shortened - hypercalcaemia
- Prolonged - hypokalaemia, hypocalcaemia, hypothermia, antiarrhythmics
(amiodarone, flecainide), antimicrobials (erythromycin, clarithromycin,
fluconazole, ketoconazole), antipsychotics, antidepressants, antiemetics
- ST segment: isoelectric
- Elevated - normal variant (high take-off), STEMI, vasospastic/variant/Prinzmetal
angina, acute pericarditis (saddle-shaped)
- Depressed - normal variant (upward sloping), NSTEMI, posterior MI (V1-V3),
unstable angina, digoxin effect (downward sloping)
- T wave: inverted in aVR and sometimes aVL, III, V1, V2 and V3
- Abnormal if inverted in I, II, aVF, V4-6
- Inverted in V5 and V6 - digoxin effect (reversed tick)
- Peaked - hyperkalaemia, TCA overdose, within a few hours of an MI
- Flattened - hypokalaemia, hypocalcaemia, within 24 hours of an MI
- Other waves:
- J wave - hypothermia
- U wave - hypokalaemia
- Delta wave - Wolff-Parkinson-White syndrome
Hyperkalaemia - tall tented T waves, prolonged QRS complex, absent P waves, ‘sine wave’
pattern
Hypokalaemia - “In hypokalaemia U have no Pot and no Tea, but a long PR and a long QT”
, I Lateral aVR V1 Septal/anterior V4 Anterior
Left circumflex artery LAD LAD
II Inferior aVL V2 Septal/anterior V5 Lateral
RCA LAD Left circumflex artery
III Inferior aVF Inferior V3 Anterior V6 Lateral
RCA RCA LAD Left circumflex artery
- SAN - RCA in 60%, left circumflex artery in 40% (sinoatrial node branch)
- AVN - RCA in 80%, left circumflex artery in 20% (atrioventricular node branch)
ANGINA
- Constricting discomfort in the chest, neck, shoulders, jaw or arms caused by an insufficient
blood supply to the heart
- #1 coronary artery disease (other causes include valvular heart disease (aortic
stenosis), HOCM, hypertension)
- Stable angina - occurs with exertion or stress, relieved by rest or GTN within 5m
- Unstable angina - occurs at rest, new onset or abrupt deterioration of stable
angina, follow ‘NSTEMI and unstable angina’ tx
- Vasospastic/variant/Prinzmetal angina - due to coronary artery spasm,
ECG during pain shows ST elevation
- Canadian Cardiovascular Society grading
- Class I - sx on strenuous exertion
- Class II - sx on moderate exertion
- Class III - sx on mild exertion
- Class IV - sx at rest
- Dx: full hx, bedside (BP, ECG), bloods (for conditions which exacerbate)
- Tx: assess QRISK score (>10% consider primary prevention dose statin)
- Acute - sublingual GTN
- Chronic - #1 BB or CCB then increase dose then BB + CCB
- #2 long-acting nitrate, nicorandil, ivabradine, ranolazine
- Remember if CCB monotherapy use non-dihydropyridine rate-limiting CCB
(verapamil or diltiazem) and if dual-therapy use dihydropyridine (nifedipine)
- Tolerance can develop to (standard release) isosorbide mononitrate, if
tolerance develops then take 2nd dose at 8h not 12h to maintain
concentrations
ACUTE CORONARY SYNDROMES (ACS)
- STEMI and NSTEMI have troponin rise due to (mainly LV) myocardial cell death, unstable
angina does not
- But also raised in any cause of LV dysfunction, interventions which ‘damage’ the
heart (CPR, defibrillation, cardioversion, ablation) and renal failure
