Cardiac Arrhythmias in Acute Coronary Syndrome Roj Rojjarekampai, MD Thammasart Hospital 26/5/59
OUTLINE Management of tachy and brady-arrhytmia related ACS : AF : VA [ sustained VT /VF] : conduction disturbance
AF and ACS AF occurred in MI 2.3-21 % Pre-existing AF accounts for 1/3,the remaining was newonset AF Early reperfusion therapy has led to decline of incidence of post-mi AF
Consequence of AF in MI Significant worsening of hemodynamics came from high ventricular rate and loss of atrial contribution, that results in decrease of CO and HF Increase mortality and ischemic stroke during hospitalized or F/U ( even reverse back to SR before D/C)
Pooled data from 120,566 MI AF occurred 7.5% 8 vs 6.4 % From 10 clinical tri HR for 7 day mortality : 1.65 HR for 8-365 day mortality : 2.37
HR for 7 day mortality : 2.30 HR for 8-365 day mortality : 1.67
AF & short-term Mortality in ACS STEMI NSTEMI
AF & long-term Mortality in ACS STEMI NSTEMI
New onset AF and MI mortality
Pre-existing AF and MI mortality
MANAGEMENT OF AF IN ACS
rate vs rhythm control Rhythm control was considered when : ongoing ischemia, severe hemodynamic compromised : electrical cardioversion triggers or secondary causes was corrected but AF still medical cardioversion
AF in ACS Unstable V/S considered DCC Drugs : amiodarone : betablocker : non-dhp CCBs : digoxine in HF patients : avoid Ic
Stroke risk stratification All pts of ACS with AF will have score of CHA2DS2VASc =1 Those will be candidated for OAC Most pts will be treated with PCI and stenting, are indication for DAPT Triple therapy for a defined period usually required
Stroke risk stratification
Triple therapy
Triple therapy in ACS O-A-C for 4 wks ( high HASBLED) or for 6 mo ( low HASBLED ) ( INR of 2-2.5 is preferred ) Then continue with O-C (A) until 12 months Finally, life-long use of oral anticoagulation
VAS IN ACS
VAs and ACS In STEMI : incidence decrease from 10 % in fibrinolytic era [ GUSTO-1] to near 6 % in primary PCI era [ APEX- AMI] 90% occurred in first 48 hrs Ass with increase mortality
VAs and ACS In NSTEMI ; VA incidence 1.5-2% in contemporary era Frequency of VA in first 48 hrs is similar to after 48 hrs Median time to development of VA is 5 days VA have impact on mortality
Pooled 26,416 NSTEMI VT&VF VF VT NO VT/VF
Predictors for VAs
Substrates for VAs Pre-existing low LVEF Myocardial scar Increase sympathetic activity Cardiogenic shock Genetic predisposition
Mechanism of VT in CAD Re-entry : MI scarring Enhanced automaticity : VT arising from ischemic border during acute ischemia,myocarditis,cocaine intoxication AIVR Triggered activity : oscillating of membrane potential ; also likely to be initiated during ischemia
VT/VF in ischemia
Triggered activity
Myocardial ischemia Net cellular K loss Net cellular Na gain Decrease intracellular ATP content Increase intracellular proton generation
Treatment of VAs in ACS
prophylactic AADs not suitable optimal revascularization,early Rx with BB, balancing Elyte,sedation, DCCV / overdrive stimulation should be considered first if AADs is needed ( recurrent VAs related-acs after failure available Rx),IV Amiodarone and followed by IV Lidocaine is reasonable
ACC 2013 prophylactic antiarrhythmics are not recommended for patients with suspected ACS or myocardial infarction in the prehospital or ED (Class III, LOE A).
ACC 2013 Routine IV administration of -blockers to patients without hemodynamic or electric contraindications is associated with a reduced incidence of primary VF (Class IIb, LOE C).
ACC 2013 Following an episode of VF, there is no conclusive data to support the use of lidocaine or any particular strategy for preventing VF recurrence.
COMMIT/CCS-2: Clopidogrel and Metoprolol in Myocardial Infarction Trial/Second Chinese Cardiac Study -- The Metoprolol Arm The study enrolled patients with suspected acute MI (ST change or new left bundle branch block) within 24 hours of symptom onset; patients with shock, systolic blood pressure < 100 mm Hg, heart rate < 50 min, or second- or third-degree atrioventricular block were excluded. Patients were randomized to receive 3 doses of metoprolol 5 mg IV over the course of 15 minutes, followed by 200 mg oral daily for the remainder of the hospitalization or to matching placebo.
ACC 2013 It is prudent clinical practice to maintain serum potassium 4 meq/l and magnesium 2 meq/l (Class IIB, LOE A).
Electrical Rx SVT AF VT VF
AIVR
Reperfusion Arrhythmias
Arrhythmias in STEMI - related primary PCI
AIVR ; CAVEAT AIVR is one of the reperfusion arrhythmias AIVR is not specific sign of successful reperfusion Rx Most AIVR does not need for specific Rx Clinical correlation of patients is essential
AICD
AICD and ACS Secondary prevention
Amiodarone Cordarone I.V. Side-Effects and Incompatibilities: PolySorbate 80 (or Tween 80) Hepatotoxicity, severe hypotension, cardiac depression BzAlcohol: CNS depression, acidosis, respiratory failure Foams complicating required dilution and delivery Irritating, phlebitis Incompatible with plastics
conduction disturbance in MI
AVB Incidence of new onset AVB in STEMI has decreased in reperfusion era from 5-7% to 3.2 % [ throbolytic to PCI era ] High grade AVB ass inf wall MI located above His 90%, while ass with ant MI most located below AVN Only 9 % of these patients required permanent pacing
BBB RBBB or LBBB can be occurred depend on culprit coronary occlusion LAD : RBBB with LAFB RCA : LPFB LAD & RCA : CLBBB
Rx of conduction disturbance in ACS Prompt opening of infarct-related artery is sufficient esp in AVB in setting of inferior wall MI TPM is indicated only in threatening bradycardia not resolving after successful reperfusion PPM is considered for disturbances that persist beyond acute phase after MI
Cardiac pacing in ACS No evidence of benefit of cardiac pacing in setting of new onset BBB ass with transient high grade AVB [ has been historically indication ]
สร ป Both AF and VA have impact on mortality in ACS Patients Prompty and correct treatments by multi-modality should be strictly performed to ACS patients Prevention of late- complication after revascularization should be concerned( stroke & SCD )