Transcript Post MI Ventricular Septal Defects

Post MI Ventricular Septal
Defects
Nick Tehrani, MD
Overview
VSD Complicates 1-2% of cases of
acute myocardial infarction.
First successful correction reported by
Cooley in 1957.
Overview
High mortality despite various
improvements in therapy
30 day mortality- 74%
1 year mortality- 78%
GUSTO analysis, Crenshaw et al,
Circ. 1/2000
Overview
Relative Improvement in survival due to
Earlier diagnosis
Earlier flow restoration
More aggressive surgical intervention
Overview
Incidence declining due to:
Earlier restoration of flow, preventing
transmural MI
More aggressive BP control post MI
Overview
Predictors of VSD
Advanced age,
Anterior location of infarction,
Female sex,
No history of smoking
Per GUSTO analysis
Thrombolysis after 12 hours also
suggested as a predisposing factor.
Overview
Average time to rupture
2-4 days
Range: few hours  2 weeks
Time course may be accelerated by
thrombolysis, possible related to
intramyocardial hemorrhage
Overview
Coronary anatomy and VSD
Post MI VSDs more commonly
associated with 100% occlusion of the
infarct related artery
This was observed in all of our
patients
Anatomy of VSDs
Two types of VSD
Simple: through and through defect usually
located anteriorly
Complex: serpentiginous dissection tract
remote from the primary septal defect- most
commonly an inferior VSD
Patient BG had such a presentation
Transesophageal Echocardiogram of
Complex VSD
Angiography
Anatomy of VSDs
Antro-apical septal rupture
Comprise approximately 60-80% of
cases
LAD occlusion is always the culprit
Anatomy of VSDs
Posterior septal rupture
Approximately 20-40% of cases
Occlusion of
Dominant RCA => extensive RV
infarction
Dominant LCX (Less common), RV
mostly spared
Anatomy of VSDs
Multiple defects (5-11% of cases)
Secondary to infarct extension
Evolve within days of each other
Anatomy of VSDs
Our series
Antro-apical septum
Three of four cases
Posterior septum
One of four cases
Pathophysiology
Antero-apical septal rupture
Tamponade
Secondary RV failiure due to acute volume
overload
Pathophysiology
Posterior septal rupture
Commonly complicated by MR
Shunt reversal due to elevated RVEDP
Diagnosis
Loud/harsh pansystolic murmur
Within the first week post AMI
Best heard at Lt. Lower sternal border
Less loud at the apex
Associated with a palpable thrill
Depending on the location, may radiate to
the axilla mimicking MR
Diagnosis
Up to 50% of patients experience chest
pain associated with the development
of murmur
CHF and shock often associated with
the development of murmur
Diagnosis
Color Flow Doppler
100% sensitive and specific in differentiating VSD
from acute MR
Site of septal rupture correctly identified in 41 of
42 patients
One of our 4 patients had had a negative TTE
earlier in the day, and no apparent homodynamic
changes prior to the catheterization later that day
Smyllie et. Al. 1990 JACC
Diagnosis
Earlier diagnosis and surgical
intervention, may be due to greater
availability of Echocardiography at
peripheral centers.
Diagnosis
Need for cardiac catheterization
2/3 of the patients have multivessel
coronary artery disease
Decreased operative mortality and
improved late survival has been shown in
patients with multivessel disease
Cardiogenic shock not a deterrent to Cath
=> Coronary angiography
should be performed
Diagnosis
Pre-Operative Management
Hemodynamic stabilization so as to
minimize peripheral organ compromise
Reduce Systemic vascular resistance, and
thus, the left-to-right shunt
Maintain or improve coronary artery blood
flow
Maintain cardiac output and arterial
pressure to ensure peripheral organ
perfusion
=> IABP
Timing of Surgery
Controversial (in the past)
Non-randomized studies showing:
Early repair, 40% - 50% mortality
Late repair (past 3 weeks), 10% mortality
=>
Aggressive Medical management aimed
at delaying surgical intervention
Timing of Surgery
Short-coming of the argument
Patients with less sever hemodynamic
compromise, more likely to survive the acute
phase without need for prompt surgery:
Lower pre-op risk =>Better outcome
Timing of Surgery
Short-coming of the argument
Patients with greater hemodynamic
compromise, and more severe insult:
Higher pre-op risk =>Worse outcome
Timing of Surgery
Surgery should be performed soon after
diagnosis in most patients
Patients is cardiogenic shock should be
operated on immediately after
anigography
Hemodynamically stable patients should
have surgery on an urgent basis
Operative Technique
Classical approach to
antero-septal rupture
Infarctectomy, and
Reconstruction of the
ventricular septum
with Dacron patches
Operative Technique
Classical approach
to infro-posterior
rupture
Infarctectomy, and
Reconstruction of
infroposterior VSD,
Reconstruction free wall
with Dacron patches.
Outcome
In a review of 139 cases reported in
the literature prior to 1977
Six month survival without
surgical intervention was less
than 10%.
Kirklin, Churchill Livingston 1993
Outcome
Predictors of early mortality per
multivariable logistic regression analysis
in a series of 22 patients
DM
Elevated RA pressure (RV involvement/IMI)
Absence of intraoperative IABP
Outcome
Predictors of early mortality per
GUSTO analysis
Advanced age
Inferior location of MI
Outcome
In patients with cardiogenic shock mortality
reported to be the highest
Posterior VSD (IMI) is another factor strongly
associated with poor surgical outcome due to
Difficulty of exposure, and
Frequent concomitant infarction of the posteromedial papillary muscle
Compilation from 6 series from the late 80s
Outcome
David, in a series of 44 patients
reported no difference between
mortality rates for the posterior and
anterior VSD using the
Exclusion technique
Exclusion Technique
Exclusion technique
LV excluded from the infarcted muscle
using a bovine pericardial patch sutured
to the healthy peri-infarct endocardium
No infarctectomy is performed
RV is undisturbed
Better RV function preservation
May help support the posteromedial
papillary muscle
Exclusion technique
Exclusion
technique
Outcome
Residual Lt.  Rt. shunt
Reported in up to 28% of survivors
Associated with high mortality
Intra-operative TEE useful in early detection
and correction if deemed necessary
Seen in one of our patients.
Patient was treated medically
Residual VSD
Post-Op state
Dialysis
Commonly required in patients in shock
Not required by either of our two survivors
Prolonged ventilatory support
Residual or recurrent VSD
Reoperation may be necessary depending
on the shunt size and hemodynamics
Clinical Profile of our Patients