Cardiovascular Flashcards
(155 cards)
Anteroseptal, inferior, lateral leads and which coronary artery they cover?
Anteroseptal = V1-V4 (LAD)
Inferior = II, III and aVF (RCA)
Lateral = I, aVL, V5, V6 (LCx)
Normal P, PR and QRS duration?
P = 0.08-0.1 secs
PR = 0.12-0.2 secs
QRS = < 0.1 secs
What does a small vs large box on a standard ECG represent?
Small = 0.04 seconds
Large = 0.2 seconds
Calculating heart rate using the rhythm strip?
Regular = 300 ÷ large squares between QRS complexes
Irregular = QRS complexes in 6 seconds (30 large squares) x 10
ECG feature of right vs left axis deviation and causes?
Right = lead I + III point to each other
→ RVH, RBB, cor pulmonale, anterolateral MI, left posterior hemiblock
Left axis = lead I + II point away from each other
→ LVH, LBBB, inferior MI, left anterior hemiblock
ECG features of RBBB vs LBBB?
WiLLiaM MaRRoW:
→ RBBB = M in V1, W in V6
→ LBBB = W in V1, M in V6
Bifascicular vs trifascicular block?
Bifascicular = RBBB + left hemiblock
Trifascicular = above + 1st degree heart block
Outline the sinoatrial (SA) node action potential.
- Slow Na influx (HCN “pacemaker” channel)
- Rapid Ca influx
- K efflux
Outline the atrial/ventricular myocyte action potential.
- Rapid Na influx
- K efflux vs Ca influx (plateau phase)
- K efflux exceeds Ca influx
Virchow’s triad?
Stasis of blood
Endothelial damage
Hyper-coagulability
Heart attack vs cardiac arrest?
Heart attack = vascular occlusion or ischaemia leads to tissue death
Cardiac arrest = electrical disturbance stops heart beat
Acute coronary syndromes and ECG/troponin findings?
Unstable angina = abnormal/normal ECG + normal troponin
NSTEMI = abnormal/normal ECG + raised troponin
STEMI = ST-elevation/new LBBB + raised troponin (not required)
Patient groups more likely to have an atypical ACS presentation?
Elderly
Diabetics
Women
ECG features of ischaemia?
ST elevation or depression
T wave elevation or inversion or flattening
New LBBB
Pathological Q waves
ECG criteria for STEMI diagnosis?
≥ 1mm ST elevation in any 2 contiguous leads except V2 and V3 where these criteria apply:
→ ≥ 2.5mm in men < 40
→ ≥ 2mm in men > 40
→ ≥ 1.5mm in women
ECG feature of posterior MI?
Reciprocal changes in leads V1-V3 (e.g. ST depression)
Which coronary artery supplies the atrioventricular (AV) node and significance?
Right coronary artery
RCA infarcts (e.g. inferior MI) can cause arrhythmias
Management of a STEMI?
Morphine (severe pain)
Oxygen (SaO2 < 94%)
GTN (not if hypotensive)
Aspirin 300mg
Ticagrelor or prasugrel or clopidogrel
PCI < 120 mins = PCI + UFH and GPI (radial access) or bivalirudin and GPI (femoral access)
PCI > 120 mins = thrombolysis + fondaparinux
Preferred antiplatelet for patient getting PCI vs high bleeding risk?
PCI = prasugrel
High bleeding risk = clopidogrel
ECG monitoring post-thrombolysis?
ECG after 60-90 mins
Consider PCI if ongoing ischaemia
List some contrindications to thrombolysis?
Bleeding/coagulation disorder
Active internal bleeding
Recent bleed, trauma or surgery
Stroke < 3 months ago
Severe hypertension
Intracranial neoplasm
First enzyme to be released in MI and enzyme used to assess re-infarction?
First to be released = myoglobin
Assessing for re-infarction = CK-MB
Most sensitive enzyme in MI, time of elevation, peak levels and when it return to normal?
Troponin
→ elevates in 4-6 hours
→ peaks at 12-24 hours
→ returns to normal at 7-10 days
Post-MI persistent ST-elevation and ventricular failure?
Left ventricular aneurysm