Cardiology Flashcards
What are the events of the ischemic cascade with increasing ischemic time (5)?
- Blood flow changes (can be seen on myocardial perfusion)
- Diastolic –> systolic dysfunction (wall motion abnormalities)
- ECG changes
- Symptoms
- Myocardial necrosis
What are the diagnostic tests for CAD?
- Functional
- stress: exercise or drugs (inotropes, vasodilators)
- test: ECG, ECG+echo, ECG+nuclear - Structural
- angio
- CT angio
What are the contraindications to treadmill stress testing?
- Recent MI (< 4 days)
- UA
- Severe symptomatic LV dysfunction
- Likfe threatening arrhythmia
- Acute pericarditis
- PE
- Severe (or symptomatic) aortic stenosis
- Uninterpretable ECG (STD > 1mm, digoxin, pre-excitation, paced, LBBB)
What constitutes a positive stress test? What are the high-risk features?
Achieved 85% maximal HR
>1mm horizontal or down-sloping STD over multiple leads
High risk features:
1. >/=2mm STD; STD with <5 METS or persisting > 3min into recovery
- Exercise induced:
- STE
- VT/VF
- SBP drop by > 10 mmHg - Inability to increase SBP to > 120 with exercise
> 3% annual risk of death/MI if untreated
What is involved in an MPI? What can cause false negative results? What are contraindications to testing?
First line if unable to complete ECG stress test
Concept: coronary perfusion mismatch
-vasodilator (dipyridamole) given –> diseased vessels already max dilated –> flow “steal” by healthy arteries –> perfusion mismatch
False negative:
- Drugs that interact with dipyridamole (caffeine, theophylline)
- “Balanced ischemia” (severe triple vessel or left main disease)
Contraindications:
- active asthma/COPD (DP can induce bronchospasm)
- reversal agent: aminophylline
When is a coronary artery calcium (CAC) score indicated?
Risk stratification of intermediate risk FRS (10 - 19%) who would otherwise not be statin-candidates
-High CAC (>100) –> statin recommended
Not currently covered by OHIP or recommended due to radiation risk
What are the indications and contraindications for coronary CT angiogram (CCTA, different from CAC)? What does one do with the results?
Low dose CT under BB +/- IV nitro: target HR < 60, breath hold
Indications:
- workup of ischemic symptoms in low-intermediate pre-test probability patients
- risk stratification in patients with stable CAD
Contraindications:
- ACS
- severe structural heart disease (AS or HCM)
- usual CT precautions (contrast allergy, renal failure, pregnancy)
If suggestive of CAD –> medical treatment (ASA + statin)
What is the management of chronic stable CAD?
- Symptomatic improvement:
- BB
- CCB
- nitrates - Mortality benefit
- ASA (+/- low-dose rivaroxaban per COMPASS trial)
- smoking cessation, exercise, diet
- optimize risk factors: - HTN: ACEi
- DLP: high-dose statin, target LDL-C < 2 and 50% drop
- DM: A1c < 7%
- OSA: CPAP (but doesn’t seem to change CV outcomes)
OMT = revascularization (COURAGE, ISCHEMIA trials)
Revascularization if refractory to meds OR high risk structural disease (left main)
In stable CAD, when
is CABG preferable to PCI? Why?
CABG:
- left main (>50%)
- multivessel + DM
- multivessel + LV dysfunction/CHF
CABG v PCI:
- Stroke data conflicting between NOBLE and EXCEL
- less repeat revasc with CABG
- no clear mortality difference
What are the four pillars of ACS management (acute and long-term)?
- Immediate medical management
- Reperfusion
- Risk factor optimization
- Driving
What are the three component of immediate medical management in ACS?
- Antiplatelets
- ASA + 2nd agent
- loading doses: ASA 160 (chewed), Ticagrelor 180, Clopidogrel 300-600
- Ticagrelor CI if prior ICH
- thrombolysis –> ASA + Plavix (no ticagrelor or prasugrel) - Anticoagulation
- UFH, LMWH or fonda - Anti-anginal
- BB within 24h if stable
What are the reperfusion time-targets for ACS? When is PCI superior to fibrinolysis?
- PCI capable centre: FMC to balloon < 90 min
- Non-PCI capable centre: FMC to balloon < 120 min
- fibrinolysis chosen: FMC to needle 30min
PCI > fibrinolysis if:
- Timely (see above)
- Late presentation (12-24h after symptom onset)
- Cardiogenic shock
If lysis given, “drip and ship” (send to PCI centre for PCI within 24h)
What are the indications and contraindications specific to each 2nd antiplatelet agent (ticagrelor, clopidogrel, prasugrel)
- Ticagrelor
- first line for ACS
- more potent than clopidogrel: greater efficacy but higher bleed risk
- CI if prior ICH, active bleeding, mod-sev hepatic impairment, or in combination with CYP34Ai (ketoconazole, clarithromycin, ritonavir)
- Consider avoiding in heart block or bradycardia - Clopidogrel
- elective PCI (only agent studied)
- fibrinolysis (only agent studied)
- AFIB on DOAC - Prasugrel
- CI in age > 75, prior stroke (ischemic or bleed)
When should NSTEMI be reperfused?
Intermediate/high risk: early invasive strategy
- angio +/- PCI within 48h
- reduced rehospitalization and ischemia but not mortality benefit
Low risk or unclear diagnosis: non-invasive stress test (usually with functional imaging) first
What are the three options for PCI, their benefits and drawbacks?
- Plain old balloon angioplasty (POBA)
- rarely done - Bare metal stent
- endothelialize quickly (shorter DAPT required)
- higher rates of re-stenosis - Drug eluding stent
- take longer to endothelialize (longer DAPT required)
- lower rates of restenosis
What are DAPT durations (no AFIB)?
- Post-MI: 12 months
- min durations per below if urgent procedure required - Elective PCI
- BMS: 6 - 12; min 1
- DES: 6 - 12; min 3
DAPT > 1 year if well tolerated and low risk for bleeding
- evidence up to 3 years
- ASA + ticagrelor (60 BID) or clopidogrel (75 daily)
List the clinical and angiographic factors that constitute high risk for thrombotic events
Clinical:
- prior STEMI/NSTEMI
- DM
- CKD
- prior stent thrombosis
- smoker
Angiographic:
- multiple (3+) stents or lesions stented or use of a biodegradable vascular scaffold
- long lesion (>60 mm stent length)
- Complex lesion (bifurcation with 2 stents, stenting of chronic occlusion)
- LM or pLAD stent
- Multivessel PCI
What is the peri-operative management of anti-platelets?
Elective non-cardiac surgery:
- BMS: delay at least 1 month post-PCI
- DES: delay at least 3 months post-PCI
Pre-op:
- Hold Plavix/Ticagrelor 5 -7d prior
- continue ASA “whenever possible”
Post-op:
-Restart DAPT as soon as safe
Name four categories of post-ACS complications
- CHF
- Arrhythmias
- tachy: atrial, ventricular
- bradycardia, heart block (especially in inferior MI) - Mechanical
- pap muscle rupture/MR
- wall rupture (VSD, free wall)
- RV infarct (esp. inferior) - Pericarditis
- Dressler Syndrome: fever + pericarditis. Rx high dose ASA + colchicine
What are the driving restrictions post-ACS?
STEMI: 1 month/3 months (private/commercial)
NSTEMI + WMA: same as STEMI
CABG: same as STEMI
UA/NSTEMI w PCI: 48h/7d
UA/NSTEMI w/o PCI: 7d/1 month
Elective PCI: same as UA/NSTEMI w PCI
List 7 categories of causes of dilated CM
- Ischemic
- INfectious (viral, HIV, Chagas)
- Peri-partum
- Stress-induced (Takotsubo)
- Tachyarrhythmia
- Toxic (drugs, chemo, EtOH)
- Idiopathic (genetic: 30 - 40%)
List three mechanisms that result in restrictive CM and give examples for each.
- Infiltration: amyloidosis, hemochromatosis, sarcoidosis
- Myocardial fibrosis: CTDs like scleroderma
- Endocardial fibrosis: radiation, tumour, eosinophils
What are the management principles for HoCM (5)?
- Family screening & genetic counseling for 1st degree relatives
- Avoidance of hypovolemia/decreased LV volume
- Beta-blockers for everyone
- Procedure for some (septal ablation or myomectomy)
- ICD if:
- sustained VT or prior cardiac arrest
- FmHx of sudden death, LV wall thickness > 30mm, unexplained syncope
What are the cardiac manifestations of amyloidosis? List seven extra-cardiac manifestations.
Cardiac:
- CHF (from restrictive CM)
- syncope (ventricular arrhythmias)
- afib/flutter
- conduction system disease
- low-flow, low-gradient AS
May also have:
- Neuropathy
- LE neuropathy
- Carpel tunnel syndrome
- Autonomic neuropathy (orthostatic hypotension, gastroparesis, sexual dysfunction, sweating abnormalities) - Renal insufficiency/nephrotic syndrome
What are the normal pressures of the cardiac chambers?
RA: 7
RV: 35/8 (S/D)
PA: 35/12/20 (S/D/Mean)
PCWP (est. LAP/LVEDP): 12
What are the pharmacologic therapies to improve LVEF and mortality in HFrEF (6)?
- ACEi/ARB
- BB (carvedilol, bisoprolol, metoprolol succinate)
- MRA (spironolactone, eplerenone)
- ARB/neprolysin inhibitor (Entresto)
- SGLT2i
- ISDN-hydralazine (in black patients or intolerant to ACEi/ARB)
Avoid CCB when EF < 40%
- amlodipine generally safe but can worsen edema
- avoid diltiazem/verapamil entirely
When are SGLT2i indicated?
- T2DM plus:
- CAD
- HFrEF
- proteinuric CKD
- age > 50 + RF for CAD - HFrEF without T2DM
Describe the algorithm for the long-term management of HFrEF.
Triple therapy (ACEi/ARB + BB + MRA)
if T2DM: SGLT2i
–>
NYHA II - IV:
- switch ACEi/ARB to Entresto
- SR, HR > 70 –> ivabradine
- consider SGLT2i even if no DM
–>
EF > 35 –> CCM
EF < 35
–>
NYHA I - III:
-ICD/CRT
NYHA IV:
- consider hydralazine/nitrates
- referral for advanced HF or palliative care
When can beta blockers be safely used in HF?
NYHA IV pts should be stabilized prior to initiation
If a chronic med, continue in acute heart failure unless hypotensive or bradycardic
What are the indications for ICD for PRIMARY prevention? What are the indications for secondary prevention?
PRIMARY
LVEF = 35%
- despite 3 months of OMT
- min 1 month post-MI and 3 months post-revascularization
- NYHA II-III
- NYHA I + CAD + EF < 30%
- NYHA IV should NOT get an ICD if not predicted to improve further or are not candidates for advanced therapies (transplant, mechanical circulatory support)
SECONDARY
- Cardiac arrest
- Sustained VT + significant structural heart disease
- Sustained VT > 48h post-MI or revascularization
- Syncope + structural heart disease where syncope presumed 2’ to VT/VF
Above only apply if NO REVERSIBLE cause is found
*Sustained VT = VT lasting > 30sec or hemodynamically significant
What are the indications for CRT?
Major indications: LVEF = 35% AND -NYHA II - IV despite 3+ mo OMT -sinus rhythm -LBBB w QRS >/= 130
Consider if QRS > 150 (and no LBBB), afib, elderly/frail, chronic RV pacing with reduced EF
Add ICD (CRT-D) if criteria for ICD also met; otherwise CRT-P
Can upgrade PPM to CRT if criteria met
What are the principles of management for HFpEF?
- Treat HTN (usually ACEi/ARB)
- Diuretics for congestive symptoms
- Consider MRA for elevated BNP
- Treat comorbidities
- DM: metformin, SGLT2i reasonable. Avoid saxagliptin and thiazolidinediones