Related Experiment Videos
[Effect of aortic valve replacement on left ventricular function in adult patients with aortic stenosis]
1Department of Cardiovascular Surgery, School of Medicine, Hokkaido University, Sapporo, Japan.
Insights
Aortic valve replacement (AVR) significantly improves left ventricular (LV) function in patients with aortic stenosis (AS). This surgery reverses LV dysfunction caused by AS, leading to substantial clinical recovery and improved heart performance.
Area of Science:
- Cardiology
- Cardiac Surgery
- Biomedical Engineering
Context:
- Aortic stenosis (AS) is a progressive condition often requiring surgical intervention.
- Aortic valve replacement (AVR) is a standard treatment for severe AS.
- Assessing the impact of AVR on left ventricular (LV) function is crucial for understanding long-term outcomes.
Purpose:
- To evaluate the effects of AVR using St. Jude Medical valves on echocardiographic and hemodynamic parameters in adult patients with AS.
- To determine if depressed LV function in AS patients is reversible after AVR.
- To correlate changes in LV function with clinical improvement post-AVR.
Summary:
- 16 adult patients with AS underwent AVR. Postoperative echocardiography and hemodynamic studies revealed significant improvements in LV function, including reduced LV dimensions, increased fractional shortening, and decreased end-systolic wall stress.
- NYHA functional class improved significantly, with most patients moving from class II/III to class I/II.
- One patient experienced late cardiac tamponade, but overall, AVR led to substantial clinical and functional recovery.
Impact:
- LV dysfunction in AS is largely reversible, primarily due to mechanical unloading of the left ventricle and improved preload reserve.
- AVR effectively corrects the afterload mismatch caused by AS, restoring LV systolic function.
- The study demonstrates that AVR is a highly effective treatment for AS, leading to significant improvements in cardiac performance and patient quality of life.
Abstract:
Echocardiographic and hemodynamic studies were obtained in 16 consecutive adult patients who underwent aortic valve replacement (AVR) with St. Jude Medical valve for aortic stenosis (AS). Three cases of congenital AS was included and two of them had undergone aortic valvotomy in childhood. One of 16 patients died due to late cardiac tamponade six weeks after AVR. Postoperative studies showed improved left ventricular (LV) functions. LV end diastolic and end systolic diameter (LVDs and LVDs) fell from 50.3 and 38.2 to 44.6 and 31.6 mm respectively (p less than 0.05). Fractional shortening (%FS) rose from 26.5 to 32.2% (p less than 0.05). End systolic wall stress (ESWS) fell from 126.2 to 69.6 k dynes/cm2 (p less than 0.01). Cardiac index and pulmonary arterial wedge pressure improved from 3.4 and 14.4 to 3.6 l/min/m2 and 10.5 mmHg respectively (ns). Preoperatively, six were functional class II, eight were class III and one was class IV (New York Heart Association classification). Postoperative improvement was as follows, eight: class I, seven: class II. In four cases, preoperative echocardiography revealed most depressed LV function in %FS (smaller than 21%) and ESWS (greater than 140). Postoperatively they improved from 18.3 and 164 to 26.0% and 72.8 k dynes/cm2 respectively. These results suggested that depressed LV function in the patients with longstanding AS was largely related to limited preload reserve due to LV enlargement and mechanical unloading of LV (correction of afterload mismatch) resulted in improvement of LV function. In conclusion, LV dysfunction owing to AS alone is reversible and AVR results in great clinical improvement.