Essential Revision Notes for MRCP Third Edition - PasTest

Cardiology1.2.6 24-hour ambulatory bloodpressure monitoringThe limited availability and relative expense ofambulatory blood pressure monitoring prevents itsuse in all hypertensive patients. Specific areas ofusefulness include the following situations:• Assessing for ‘white coat’ hypertension• Borderline hypertensive cases that may not needtreatment• Evaluation of hypotensive symptoms• Identifying episodic hypertension (eg inphaeochromocytoma)• Assessing drug compliance and effects(particularly in resistant cases)• Nocturnal blood pressure dipper status (nondippersare at higher risk)1.2.7 Computed tomography (CT)CT has theoretical capability in both anatomical(coronary arteries, chamber dimension, pericardium)and functional (contractility, ischaemia, viability)assessments of the heart. It is the gold standardinvestigation for:• Pulmonary thromboembolic disease• Anatomical assessment of the pericardium (eg insuspected constriction)• Anomalous coronary artery origins (reliableimaging of the proximal third of major coronaryarteries)• Extramyocardial mediastinal massesOther indications include assessment of:• Chamber dimensions• Myocardial function, perfusion and ischaemia1.2.8 Magnetic resonance imaging(MRI)Cardiac MRI is the gold standard technique forassessment of myocardial function, ischaemia, perfusionand viability, cardiac chamber anatomy andimaging of the great vessels. It has a useful adjunctiverole in pericardial/mediastinal imaging. Majordrawbacks are its contraindication in patients withcertain implanted devices (eg pacemakers) andtime (consequently also cost), as a full functionalstudy can take about 45 minutes. The contrast used(gadolinium), while not directly nephrotoxic, is subjectto increased risk of metabolic toxicity in renallyimpaired individuals.Chief indications of cardiac MRI:• Myocardial ischaemia and viability assessment• Differential diagnosis of structural heart disease(congenital and acquired)• Chamber anatomy definition• Initial diagnosis and serial follow-up of greatvessel pathology (especially aortopathy)• Pericardial and mediastinal structural assessment1.3 VALVULAR DISEASE ANDENDOCARDITIS1.3.1 MurmursBenign flow murmurs: soft, short systolic murmursheard along the left sternal edge to the pulmonaryarea, without any other cardiac auscultatory, ECGor chest X-ray abnormalities. Thirty per cent ofchildren may have an innocent flow murmur.Cervical venous hum: continuous when upright andis reduced by lying; occurs with a hyperdynamiccirculation or with jugular vein compression.Large AV fistula of the arm: may cause a harsh flowmurmur across the upper mediastinum.Effect of posture on murmurs: standing significantlyincreases the murmurs of mitral valve prolapse andHCM only. Squatting and passive leg raising increasecardiac afterload and therefore decrease themurmur of HCM and mitral valve prolapse, whilstincreasing most other murmurs such as ventricularseptal defect, aortic, mitral and pulmonary regurgitation,and aortic stenosis.Effect of respiration on murmurs: inspiration accentuatesright-sided murmurs by increasing venousreturn, whereas held expiration accentuates leftsidedmurmurs. The strain phase of a Valsalvamanoeuvre reduces venous return, stroke volume13