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Chronic heart failure: global left ventricular perfusion and coronary flow reserve with velocity-encoded cine MR
Gunnar K Lund1, Norbert Watzinger, Maythem Saeed
1Department of Radiology, University of California, San Francisco, 505 Parnassus Ave, Rm L-308, San Francisco, CA 94143-0628, USA.
Insights
Patients with chronic heart failure have normal resting left ventricular (LV) perfusion but severely reduced perfusion after vasodilation. Impaired coronary flow reserve (CFR) may worsen LV function.
Area of Science:
- Cardiovascular Imaging
- Cardiac Physiology
- Heart Failure Research
Background:
- Chronic heart failure (CHF) significantly impacts left ventricular (LV) function.
- Assessing global LV perfusion and coronary flow reserve (CFR) is crucial for understanding CHF pathophysiology.
Purpose of the Study:
- To quantify and compare global LV perfusion and CFR in CHF patients versus healthy volunteers.
- Utilize velocity-encoded cine (VEC) magnetic resonance (MR) imaging to measure coronary sinus flow.
Main Methods:
- VEC MR imaging was used to measure coronary sinus flow in 10 CHF patients and 10 volunteers.
- LV perfusion was calculated from coronary sinus flow and LV mass.
- CFR was determined by measuring LV perfusion at rest and after dipyridamole infusion.
Main Results:
- Resting LV perfusion showed no significant difference between groups.
- Post-vasodilation, LV perfusion was less than half in CHF patients compared to volunteers (P=.03).
- CFR was significantly reduced in CHF patients (2.3 ± 0.9) versus volunteers (4.2 ± 1.5) (P=.01).
Conclusions:
- CHF patients exhibit normal resting LV perfusion but impaired perfusion post-vasodilation.
- Reduced CFR in CHF patients may contribute to the progressive decline in LV function.
- Combined cine and VEC MR imaging effectively characterizes perfusion deficits in CHF.
Purpose:
To quantify and compare global left ventricular (LV) perfusion and coronary flow reserve (CFR) in patients with chronic heart failure and in healthy volunteers by measuring coronary sinus flow with velocity-encoded cine (VEC) magnetic resonance (MR) imaging.
Materials And Methods:
MR measurements were performed in 10 consecutive patients with chronic heart failure due to coronary artery disease and in 10 volunteers. Global LV perfusion was quantified by measuring coronary sinus flow in an oblique imaging plane perpendicular to the coronary sinus with non-breath-hold VEC MR imaging. LV mass was measured by means of cine imaging that encompassed the heart. LV perfusion was calculated from coronary sinus flow and mass. CFR was measured from LV perfusion at rest and that after infusion of dipyridamole. Analysis of covariance was used to determine differences between groups. Differences within groups were analyzed by means of the Student t test for paired data. Regression analysis was used to determine correlation between CFR and LV ejection fraction.
Results:
At rest, LV perfusion was not significantly different in patients with chronic heart failure (0.46 mL/min/g +/- 0.19) and volunteers (0.52 mL/min/g +/- 0.21, P =.54). After administration of dipyridamole, LV perfusion was less than half in patients with chronic heart failure compared with that in volunteers (1.07 mL/min/g +/- 0.64 vs 2.19 mL/min/g +/- 0.98) (P =.03). CFR was severely reduced in patients with chronic heart failure compared with that in volunteers (2.3 +/- 0.9 vs 4.2 +/- 1.5, P =.01). A moderate but significant correlation was found between CFR and LV ejection fraction (r = 0.54, P =.02)
Conclusion:
Combined cine and VEC MR imaging revealed that patients with chronic heart failure have normal LV perfusion at rest but severely depressed LV perfusion after vasodilation. Impaired CFR may contribute to progressive decline in LV function in patients with chronic heart failure.