Transcript Hemodialysis Induced Cardiac Injury in Chronic Renal

Hemodialysis Induced Cardiac
Injury in Chronic Renal Dysfunction
Reference: McIntyre CW. Haemodialysisinduced myocardial stunning in chronic
kidney disease – A new aspect of
cardiovascular disease. Blood Purif.
2010;29:105–110.
• Cardiovascular disease in the hemodialysis population
continues to contribute to morbidity and mortality.
• A transient myocardial ischemia may lead to left
ventricular dysfunction (LVD).
• As a result, hemodialytic insult may lead to altered
functions in organ systems driving an even wider range
of pathophysiological processes.
• Hardening of the arteries is the most frequent cause of
heart disease in dialysis patients.
• This results in sudden cardiac arrest and heart failure.
• Prolonged dysfunction leads to a condition called as
myocardial stunning.
Myocardial Ischemic Potential in
Hemodialytic Patients
• Hemodialytic (HD) patients are prone to myocardial
ischemia.
• Myocardial stunning results from markedly reduced
coronary fl ow in the heart tissues.
• Hence, there is a demand to increased blood fl ow to the
myocardium.
• Hardening of the arterial walls and narrowing of the inner
channel of the artery have an adverse effect on myocardial
perfusion and reduces the ischemic threshold.
• Blood pressure frequently remains inadequately controlled
in a high proportion of HD patients because of their
fluctuating fluid status.
Dialysis-Induced Ischemia and
Myocardial Stunning
• For dialysis-induced ischemia, results were drawn by
using the data from ECG-based studies. In a study of 70
cohorts, myocardial stunning was assessed to evaluate
extent of HD- induced cardiac injury.
• It was manifested by development and recovery of
regional wall motion abnormality (RWMA).
• A HD-induced myocardial stunning occurred in twothirds of patients.
• Cardiac troponins (cTnT) are often elevated in dialysis
patients.
• This leads to reduced myocardial perfusion and
increase in microcirculatory stress.
Hemodynamic Stability
• There is a greater risk of hemodynamic instability in HD
patients.
• In one of the studies, the dialysate temperature was
reduced from 37°C to 35°C.
• The trials consisting of small number of patients were
relatively short-term.
• There was a signifi cant number of new RWMAs occurring
during standard dialysis.
• By improving mean blood pressure and reducing
intradialytic hypotension (IDH) episodes with either
biofeedback dialysis (BFD) or reduced-temperature dialysis,
a signifi cant reduction in the number of new
• RWMAs was observed.
Role of Large-Vessel Coronary Artery
Disease in Dialysis-Induced
Myocardial Stunning
• Myocardial blood fl ow was studied in patients with
coronary angiography.
• These patients still exhibited myocardial ischemic
response to HD.
• Secondly, patients with uremic cardiovascular
disturbances were assessed.
• The dialysis treatments were characterized by
particularly large ultrafi ltration requirements and
signifi cant relative dialysis-induced hypotension.
Long-Term Consequences of
Recurrent HD-Induced Ischemic Injury
• Long-term follow-up of HD patients with dialysis based echocardiography
to identify those suffering from HD- induced cardiac injury revealed signifi
cant effects on cardiac structure, function and patient survival.
• Those patients who did not develop HD-induced myocardial stunning
cardiac injury, by 1-year follow-up no reduction in overall LV ejection and
100% survival was observed.
• Another group who developed HD induced myocardial stunning, 28%
patients died. After 1 year follow-up of patients who survived, showed
reduction in overall LV ejection by around 10%.
• Increased left atrial volume (LAV), which is an indicator of chronic diastolic
dysfunction, is independent marker of cardiovascular risk.
• Left atrial volume indexed to height (LAVI) was a better predictor of
mortality than LV mass index, but both were displaced as independent
determinants of mortality with the addition of myocardial stunning.
• The LAVI signifi cantly correlated with number of RWMAs and
chronological age.
Potential Effects of Hemodynamic
Perturbation on Other Vascular Beds
• There are several pathologies described in
dialysis patients including silent cerebral infarct,
cerebral atrophy and leukoaraiosis.
• The gut is another potential aspect other than
brain.
• Translocation of endotoxin across gut wall is
associated with proinfl ammatory stimulus.
• The elevated endotoxin level correlate with
intradialytic instability, systemic infl ammation
and cTnT levels in patients with dialysis-induced
myocardial stunning.
Conclusion
• The procedure of HD exerts a signifi cant acute stress
upon the cardiovascular system.
• Cardiovascular disease remains the primary risk for
poor health outcomes and high mortality in patients
undergoing maintenance dialysis.
• Enhanced understanding of dialysis-induced cardiac
injury may provide novel therapeutic targets to reduce
currently excessive rates of cardiovascular morbidity
and mortality.
• Episodes of ischemia may potentially have a role in the
development of cardiac failure and as a trigger for
• arrhythmias.
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