Cardiology Flashcards
How would you treat bradycardia (e.g. someone presents with syncope, SOB, chest pain)?
Atropine is used in the first instance when someone has bradycardia and adverse clinical features (shock, syncope, ischemia i.e chest pain, HF). Dose: 500mcg IV Frequency: can repeat 3-5mins up to max of 3mg (administer up to 6 times). If bradycardia persists: 2nd line: Transcutaneous pacing (external pacing). 3rd line: isoprenaline/adrenaline infusion titrated to response
What extra drug can you use for bradycardia caused by CCB or B-blockers?
IV glucagon
What are important things to assess when someone presents with bradycardia?
1-Identifying the presence of signs indicating haemodynamic compromise - ‘adverse signs’: -shock: hypotension (systolic blood pressure < 90 mmHg), pallor, sweating, cold, clammy extremities, confusion or impaired consciousness -syncope -myocardial ischaemia -heart failure 2-The following are risk factors for asystole. Even if there is a satisfactory response to atropine specialist help is indicated to consider the need for transvenous pacing: -complete heart block with broad complex QRS -recent asystole -Mobitz type II AV block -ventricular pause > 3 seconds
What do you know about Amiodarone?
1-class III antiarrhythmic agent used in the treatment of atrial, nodal and ventricular tachycardias. 2-MOA: blocks potassium channels= inhibits repolarization= prolongs the action potential. Can also block sodium channels. 3-Limitations: -very long half-life (20-100 days). For this reason, loading doses are frequently used should ideally be given into central veins (causes thrombophlebitis) -has proarrhythmic effects due to lengthening of the QT interval interacts with drugs commonly used concurrently (p450 inhibitor) e.g. Decreases metabolism of warfarin -numerous long-term adverse effects. 4-Monitoring: TFT, LFT, U&E, CXR prior to treatment TFT, LFT every 6 months 5-Adverse E.: thyroid dysfunction: both hypothyroidism and hyper-thyroidism corneal deposits pulmonary fibrosis/pneumonitis liver fibrosis/hepatitis peripheral neuropathy, myopathy photosensitivity ‘slate-grey’ appearance thrombophlebitis and injection site reactions bradycardia lengths QT interval
IE in IVDU affects which valve?
Tricuspid valve
What is MOA of Alteplase?
Activates plasminogen to form plasmin. This degrades fibrin = breaks the thrombi.
Examples of thrombolysis agents? Indications, CI & side effects?
Examples: alteplase tenecteplase streptokinase Indicatations: STEMI, acute ischemic stroke, PE in haemodynamically unstable patient. CI: active internal bleeding recent haemorrhage, trauma or surgery (including dental extraction) coagulation and bleeding disorders intracranial neoplasm stroke < 3 months aortic dissection recent head injury severe hypertension Side-effects: haemorrhage hypotension - more common with streptokinase allergic reactions may occur with streptokinase
How would a posterior MI present on ECG?
Tall R waves in V1-V2 Coronary artery: Left circumflex & right coronary
How would you Ix a suspected PE? What next Ix to consider if negative?
Well’s score >4 = CTPA If CTPA is negative and a DVT is suspected= proximal leg vein ultrasound. *D-dimer is used to exclude PE in patients with Well’s score <4. Its ideally performed within 4hrs of presentation. *V/Q scans are offered as an alternative first-line investigation for patients with a Wells score greater than 4 who cannot tolerate CTPA due to contrast media allergy, severe renal impairment or high risk from irradiation.
What are the components of Well’s score?
Clinical feature Points Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins) 3 An alternative diagnosis is less likely than PE 3 Heart rate > 100 beats per minute 1.5 Immobilisation for more than 3 days or surgery in the previous 4 weeks 1.5 Previous DVT/PE 1.5 Haemoptysis 1 Malignancy (on treatment, treated in the last 6 months, or palliative) 1
If PE is suspected or likely, but there’s a delay in CTPA, what to do?
Interim therapeutic anticoagulation.
What ECG findings in hypokalaemia?
In Hypokalaemia, U have no Pot and no T, but a long PR and a long QT
U waves small or absent T waves (occasionally inversion) prolong PR interval ST depression long QT
Patient, 70 yr old male at GP has BP 190/110 twice at separate times. He denies any headache, blurred vision, chest pain or palpitations but has dyspnoea at rest & O/E has bibasal crepitations to mid-zones. Fundocopy is normal.
Respiratory rate 12
SpO295% on room air
Temperature36ºC
Blood pressure190/110mmHg
Heart Rate50bpm
What is the next step in Mx?
If new BP >= 180/120 mmHg + new-onset confusion, chest pain, signs of heart failure, or acute kidney injury then admit for specialist assessment.
Other same-day specialists referrals in the setting of severe HTN: retinal haemorrhages, papilloedema (signs of accelerated hypertension) or suspected phaeochromocytoma.
When would you use contrast-enhanced CT coronary angiography (CTCA)?
Typical angina
Atypical angina
Non-cardiac chest pain but a positive resting ECG e.g. Q wave abnormalities, ST-T wave changes
Management of NSTEMI & Unstable Angina?
Aspirin 300mg
Fondaparinux 2.5mg s/c for 48-72hrs (if PCI isnt planned immedietly)
Calculate GRACE score (6-month mortality)
- Low risk (<= 3%): Conservative with Tricagrelor
- Intermediate/high risk (>3%): 1- PCI (immediate if clinically unstable- within 72hrs if stable)
2-Give Tricagrelor or Prasugrel
3-Give Unfractioned heparin
What is the management of STEMI once its been confirmed?
2 Types of coronary reperfusion therapies to consider:
1- Primary coronary intervention (PCI) via drug-eluting stents= if presentation within 12 hours AND PCI can be delivered within 120 minutes of the time when fibrinolysis could have been given
OR if >12hrs but evidence of ongoing ischemia
2-Fibrinolysis/Thrombolysis= within 12 hrs onset but PCI cannot be delivered within 120 mins. Alteplase (fibrinolytic therapy) which needs antithrombin e.g Heparin.
*if patient ECG taken 90 minutes after fibrinolysis failed to show resolution of ST Elevation then PCI
What drug therapy is given for STEMI patients during PCI?
PCI via radial access: unfractionated heparin with bailout glycoprotein IIb/IIIa inhibitor (GPI)
PCI via femoral access: Bivalirudin with bailout GPI
A-What drug should be given during fibrinolysis at the same time?
B-What drug should be given following fibrinolysis procedure?
A- Antithrombin drug
B-Ticagrelor
Post-MI compliations: Acute pulmonary oedema/ CHF Mx?
IV furosemide (IV has more bioavailability in acutely ill patients)
ACE-Inhibitors + B-blockers improve long-term prognosis of patients with CHF
Symptoms of Acute PO: productive cough, SOB, anxiety & sweatiness, raised JVP, widespread end-inspiratory crackles. Low Sats, tachycardia & tachypnoea.
Specify ECG changes in STEMI:
ST elevation: occurs within minutes and may last for up to 2 weeks ( ≥2mm in adjacent chest leads and ≥1mm in adjacent limb leads is necessary to fulfil thrombolysis criteria)
Q waves: In the context of a ‘transmural infarction’, they may take hours or days to develop and usually remain indefinitely. In the standard leads, the Q wave should be ≥25% of the R wave and 0.04s in duration, with negative T waves. In the precordial leads, Q waves in V4 should be >0.4mV (four small squares) and in V6 >0.2mV (two small squares), in the absence of LBBB (QRS width <0.1s or three small squares).
ST depression: (ischaemia at distance) in a 2nd territory (in patients with ST-segment elevation) is secondary to ischaemia in a territory other than the area of infarction (often indicative of multi-vessel disease) or reciprocal electrical phenomena. Overall it implies a poorer prognosis.
PR-segment elevation/depression and alterations in the contour of the P wave are generally indicative of atrial infarction. Most patients will also have abnormal atrial rhythms such as atrial fibrillation (AF)/flutter and wandering atrial pacemaker and atrioventricular (AV) nodal rhythms.
T-wave inversion may be immediate or delayed and generally persists after the ST-elevation has resolved.
Non-diagnostic changes, but the ones that may be ischaemic: new LBBB or right bundle branch block (RBBB), tachyarrhythmias, transient tall peaked T waves or T-wave inversion, axis shift (extreme left or right), or AV block.
ACS:
A- IR to Chest pain- what is the nature of cardiac chest pain?
B-What other associated factors with chest pain?
A-Central/retrosternal position, heaviness/pressure/band-like constriction, non-pleuritic, radiates to jaw,neck,arm,shoulder. Or Atypical pain (esp/ women): epigastric, or radiate through back.
B- 1->15 mins 2-Occurs at rest (UA), 3-Inc. in frequency & duration (crescendo angina) 4-Severe 5- Nausea/Vomiting/Sweating 6-Not resolving with nitrates 7-SOB
What are the independent risk factors of ACS? what about non-modifiable?
1-hyperlipidemia, smoking, HTN, DM, CKD
2-Age, Male sex, FH (m <55, F <65), South asian ethnicity, previous MI
Silent MI- who would present with it & what other symptoms they might present with?
People with autonomic dysfunction (DM or elderly). Might present with SOB (acute Pul. Oedema, Syncope, acute confusion (mania, psychosis, delirium), hypotension/cardiogenic shock, hyperglycaemia, Stroke mimicking sec. to low CO).
Initial Ix for ACS:
1-Rapid Examination: Exclude hypotension, ?presence of murmurs & acute pulmonary oedema.
2- 12 lead ECG (15-30 mins apart)- ? Dynamic changes
3-CXR (to exclude non-cardiac causes of chest pain e.g. pneumothorax/pneumonia & to assess for HF, Pulmonary oedema & aortic dissection.
4-Bloods: a) biomarkers: Troponin T or I (6hrs apart/serial) b) FBC (anaemia) c)Urea & creatinine: impaired renal function can cause false + troponin/ need baseline for ACE inhibitors d)LFT’s: baseline for STatins, hepatic impairment is CI to ticagrelor e)Electrolytes: HypoK &HyperK cause arrhythmias, Keep K+ 4-5. f)Lipid profile-Serum cholesterol and HDL remain close to baseline for 24–48h but fall thereafter and take ≥8 weeks to return to baseline. g)Glucose: can be acutely elevated post-MI
5-Echocardiography (Echo) can be helpful to look for regional hypokinesia.
What to keep in mind about Troponin?
It has high sensitivity (can be detected easily even at very low levels) but low specificty to MI (other conditions e.g. acute HF, Myocarditis, pericarditis, PE, renal failure, stroke, tachycardia, cardiac contusion & sepsis)
NSTEMI: ECG Changes?
ST depression, T wave inversion, Flat T waves, pseudonormalisation of T waves, no ECG changes!