CRITICAL CARE
CARDIOLOGY ISSUES
ARRYTHMIAS
Yatish B. Merchant, MD, FACC
Cardiology, New Jersey
USA
Perioperative arrythmias
• Q. Commonest arrythmia seen
1.
2.
3.
4.
PAT
Atrial Flutter
Atrial fibrillation
Ventricular tachycardia
Atrial Fibrillation
• Most common arrythmia seen post op.
• Incidence 20 to 50 % after open-heart
surgery.
• Increased morbidity & prolonged ICU stay
& hospitalization with increased cost
Patterns of Atrial Fibrillation
First detected
>7 days
<7 days
Paroxysmal
(self-terminating)
Cardioversion
failed or not
attempted
May be recurrent
Permanent
(accepted)
Fuster V, et al. J Am Coll Cardiol 2006;48:854.
Persistent
(not self-terminating)
Cardioversion
failed or not
attempted
Atrial Fibrillation
• Post op AF is multifactorial.
• Many predictors have been identified.
Atrial Fibrillation
Predictors
•
•
•
•
•
•
•
•
•
Age (>65 yrs)
Sex (male)
High BMI
Hypertension (LVH)
COPD
Hypoxia
Atrial ischemia
P wave duration
Atrial pacing
•
•
•
•
•
•
•
•
•
Net fluid balance
Reduced LV EF (CHF)
Mg level
Amiodarone prophylaxis
Use of B-Blocker
Post op catecholamine use
Duration of C-P bypass
Off pump surgery
Duration of cross clamp
Triggers
•Surgical Trauma
•Anesthesia/analgesia
Inflammatory
State
↑TNF-α
↑IL-1
↑IL-6
↑CRP
•Surgical Trauma
•Anesthesia/analgesia
•Intubation/extubation
•Pain
•Hypothermia
•Bleeding/anemia
•Fasting
•Anesthesia/analgesia
•Hypothermia
•Bleeding/anemia
Stress
State
Hypoxic
State
↑ catecholamine and
cortisol levels
↓oxygen delivery
↑ BP
↑ HR
↑ FFAs
↑ relative insulin deficiency
↑ Oxygen demand
Atrial Fibrillation
Atrial Fibrillation
• Statins for prevention of AF after Cardiac
surgery (anti-inflammatory effect).
Oliver J Liakopoulos,: The Journal of Thoracic and Cardiovascular Surgery Sept 2009
Atrial Fibrillation
• Literature search : Influence of preop statin
therapy on the incidence of post op AF
• Total 17,643 pts having heart surgery.
• 58.4 % with preop. statin Rx
• 41.6 % without
Oliver J Liakopoulos,: The Journal of Thoracic and Cardiovascular Surgery Sept 2009
Atrial Fibrillation
•
•
•
•
•
Total AF incidence 24.6 %
Pre op statin group 22.3 %
Without 27.8 %
(P<0.001)
Absolute reduction 5.5%
Relative risk reduction 19.9 %
Oliver J Liakopoulos,: The Journal of Thoracic and Cardiovascular Surgery Sept 2009
Atrial Fibrillation
• AF is associated with increase long term
risk of stroke , all cause mortality,
especially in women
• Mortality rate of AF patients is 2X that of
patients in NSR with similar heart disease
• In the Framingham study, the annual risk of
stroke secondary to AF was 1.5% in
participants 50 to 59 Y old and 23.5% in
those aged 80 to 89 Y
Autonomic Influences in A fib
• Vagal A-Fib: secondary to increased
parasympathetic tone is the more common
form. (Adrenergic blockers or digitalis
sometimes worsen symptoms).
• Adrenergic A- Fib: beta-blockers are initial
treatment of choice.
• Digitalis is more effective in controlling HR
at rest in AF but less effective during
activity
Hemodynamic consequences of
A Fib
•
•
•
•
•
•
Loss of atrial contraction
Variation of R-R intervals
Decrease coronary blood flow
Increase coronary vascular resistance
Increase mean LA volume
Tachycardia induced Ventricular
cardiomyopathy
AFib Management Treatment
Options
VENTRICULAR
RATE CONTROL
Pharmacologic
Nonpharmacologic
ANTITHROMBOTIC
THERAPY
ACHIEVEMENT AND
MAINTENANCE OF
SINUS RHYTHM
Pharmacologic
Nonpharmacologic
Rhythm vs Rate Control Trials:
AFFIRM
• Randomized, multicenter trial with 4060 patients
– Elderly (mean age 69.7 years)
– 71% HTN, 65% enlarged LA, 38% CAD, 26% reduced
LVEF
– 90% AFib within 6 weeks of trial, 69% AFib duration >
2 days; 35% first episode
• Treatments compared were heart rate control (BB, CCBs,
digoxin) vs sinus rhythm control (cardioversion and AADs)
– Initial warfarin anticoagulation in both groups
– Mean follow-up 3.5 years
The AFFIRM Investigators. N Engl J Med. 2002;347:1825-1833.
Cumulative Mortality, %
Primary Endpoint of
All-Cause
Mortality:
AFFIRM
30
Rate (n=2027)
Rhythm (n=2033)
25
20
P = .08 unadjusted
P = .07 adjusted
15
10
5
0
No. Deaths
Rhythm:
Rate:
0
1
0
0
80
78
3
2
Time (years)
175
148
The AFFIRM Investigators. N Engl J Med. 2002;347:1825-1833.
257
210
4
5
314
275
352
306
When do you decide to give
Warfarin?
• A – Fib for
–
–
–
–
>7 days
>4 days
>2 days
>1 day.
Nonvalvular Atrial Fibrillation
Stroke Rates Without Anticoagulation
According to Isolated Risk Factors
15
12.5
10
7.5
5
2.5
0
Prior
Stroke/TIA
Hypertension
Age
> 75 years
Hart RG et al. Neurology 2007; 69: 546.
Female
Diabetes
Heart Failure
 LVEF
The CHADS2 Index
Stroke Risk Score for Atrial Fibrillation
Score Points
•
•
•
•
•
Congestive Heart Failure
Hypertension
Age > 75 yrs
Diabetes
Stroke (Previous TIA/CVA)
1
1
1
1
2
The CHADS2 Index
Stroke Risk Score for Atrial Fibrillation
Score
(points)
Risk of Stroke
(%/year)
0
1.9
1
2.8
2
3
4
5
6
4.0
5.9
8.5
12.5
18.2
Van Walraven C, et al. Arch Intern Med 2003; 163:936. Go A, et al. JAMA 2003; 290: 2685.
Gage BF, et al. Circulation 2004; 110: 2287.
The CHADS2 Index
Stroke Risk Score for Atrial Fibrillation
Approximate
Risk threshold for
Anticoagulation
Score
(points)
Risk of Stroke
(%/year)
0
1.9
1
2.8
2
3
4
5
6
4.0
5.9
8.5
12.5
18.2
3%/year
Van Walraven C, et al. Arch Intern Med 2003; 163:936. Go A, et al. JAMA 2003; 290: 2685.
Gage BF, et al. Circulation 2004; 110: 2287.
Atrial Fibrillation
• Current guidelines : Anticoagulation if
A-Fib > 48 hrs.
• Post op Thromboembolism occurs in <12
hrs
• Case report of AF 9 days after CABG
converted to sinus with amio & lopressor
without anticoagulation in 12 hrs had CVA.
• TEE showed clot in LAA with normal.
» Dr David Verhaert, Cleveland clinic, ohio
INR at the Time of Stroke or Bleeding
Efficacy and Safety of Warfarin
20
Odds Ratio
15
Ischemic Stroke
Intracranial
bleeding
10
5
1
1.0
2.0
3.0
4.0
5.0
International Normalized Ratio
Fang MC, et al. Ann Intern Med 2004; 141:745.
Hylek EM, et al. N Engl J Med 1996; 335:540.
6.0
7.0
8.0
Warfarin for Atrial Fibrillation
Limitations Lead to Inadequate Treatment
Adequacy of Anticoagulation in
Patients with AF in Primary Care Practice
No
warfarin
65%
Samsa GP, et al. Arch Intern Med 2000;160:967.
INR above target
6%
INR in
target range
15%
Subtherapeutic
INR
13%
Rhythm Control for AFib:
Commonly Used Oral Antiarrhythmic Drugs
Class IA
Class IC
Class III
Quinidine
Propafenone**
Sotalol
Procainamide*
Propafenone SR**
Amiodarone*
Disopyramide*
Flecainide**
Dofetilide
*Procainamide, disopyramide, and amiodarone are not FDA-approved for
treatment of AFib.
**Only propafenone, propafenone SR, and flecainide are FDA-approved for
out-patient initiation.
Miller JM, Zipes DP. In: Zipes DP, et al, eds. Braunwald’s Heart Disease. 2005.
Antiarrhythmic Drug Selection Guidelines* for Sinus
Rhythm Control in Patients with AFib
Heart Disease
No (or minimal)
Yes
Flecainide
Propafenone
Sotalol
Amiodarone,
Dofetilide
HF
CAD
Amiodarone
Dofetilide
Dofetilide
Sotalol
Catheter
Ablation
Hypertension
Substantial LVH
Yes
Amiodarone
Amiodarone
No
Flecainide
Propafenone
Sotalol
Amiodarone
Dofetilide
ACC/AHA/ESC Practice Guidelines, JACC Vol. 48 No. 4,
Aug 2006.
Catheter Ablation
THANK YOU
Atrial Fibrillation
• Lymphatic system of the heart
– (1) Subendocardial, Myocardial & epicardial
plexuses.
– (2) Drainage of conduction tissue
– (3)Main or principle lymphatic trunks (PLT)
• 1 & 2 drain in to 3 then to mediastinal LN
to thoracic duct to blood stream.
Ryszard W. Lupinski : ANZ J Surgery 2009
Atrial Fibrillation
Atrial Fibrillation
• Role of lymphatics is to protect the
interstitial space against tissue swelling,
removal of debris from injured tissue.
• Disruption >> Lymphostasis>>Interstitial
pressure rises>> swelling.
• ECG changes similar to coronary event.
Atrial Fibrillation
• Regeneration & integrity of lymphatic
vessels takes 2-20 wks depending on the
damage.
Atrial Fibrillation
• Studies have shown patients with post op
A- Fib have higher heart rate & more
frequent PAC’s.
• Autonomic nervous system imbalance is
one of the major factor for post op A-Fib.
Dr Melo: Journal of thoracic and cardiovascular surgery 2004
Atrial Fibrillation
• Ventral cardiac denervation procedure with
CABG.
Dr Melo: Journal of thoracic and cardiovascular surgery 2004
Atrial Fibrillation
• Total 110 pts. (58 & 52)
• Occurrence of AF was 7 % in Rx group &
27 % in control group (P < 0.001 )
• All 7% pts AF was less severe &
cardioverted with medicines alone.
• None of them had readmission for AF after
discharge
Dr Melo: Journal of thoracic and cardiovascular surgery 2004
Atrial Fibrillation
• Age : < 70 yrs + cardiac denervation
procedure = Reduction in AF incidence
• > 70 yrs No significant benefit
– Same number of nerves but have less axons per
nerve.
Atrial Fibrillation
• Off-pump CABG reduces the incidence of
A-Fib.
• Less invasive
• Less marked periop inflammatory response
• No cross clamp. No lymphatic interruption
Dr Hosokawa British journal of anesthesia : feb 2, 2007
Atrial Fibrillation
• What are the Predictors of AF after offpump CABG
Dr Hosokawa British journal of anesthesia : feb 2, 2007
Atrial Fibrillation
• 296 pts :
– 32% developed AF
– Most freq. on day 2.
Dr Hosokawa British journal of anesthesia : feb 2, 2007
>
<
>
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>
>
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Atrial Fibrillation
Advanced age : age related degenerative changes
seen as P wave duration & PR interval
Hypovolaemia
Low cardiac output
Higher intraoperative core temperature
– Dr Hosokawa British journal of anesthesia : feb 2, 2007
Atrial Fibrillation
• Does Minimal-Access AVR, compared to
conventional AVR, reduce the incidence of
Post-Op AF?
Bari Murtuza : Tex Heart Institute J 2008
Atrial Fibrillation
Bari Murtuza : Tex Heart Institute J 2008
Atrial Fibrillation
Atrial Fibrillation
• No difference in incidence of Post-op AF
• Benefit : 1) Fewer respiratory complication
and less blood transfusion required.
2) Cosmetically better.
• Disadvantage: 1) Longer CPB time, Longer
aortic cross clamp time. 2) More cost.
3) Increased incidence of pleural &
pericardial effusions.
Bari Murtuza : Tex Heart Institute J 2008
THANK YOU