Left ventricular regional wall motion, ejection fraction, and geometry after partial left ventriculectomy. Influence of associated mitral valve repair

Idiopathic dilated cardiomyopathy: computerized anatomic study of relashionship between septal and free left ventricle wall

Introduction

A feature of dilated cardiomyopathy is the deformation of ventricular cavity, which contributes to systolic dysfunction. Few studies have evaluated this deformation bearing in mind ventricular regions and segments of the ventricle, which could reveal important details of the remodeling process, supporting a better understanding of its role in functional impairment and the development of new therapeutic strategies.

Objective

To evaluate if, in basal, equatorial and apical regions, increased internal transverse perimeter of left ventricle in idiopathic dilated cardiomyopathy occurs proportionally between the septal and non-septal segment.

Methods

We performed an anatomical study with 28 adult hearts from human cadavers. One group consisted of 18 hearts with idiopathic dilated cardiomyopathy and another group with 10 normal hearts. After lamination and left ventricle digital image capture, in three different regions (base, equator and apex), the transversal internal perimeter of left ventricle was divided into two segments: septal and not septal. These segments were measured by proper software. It was established an index of proportionality between these segments, called septal and non-septal segment index. Then we determined whether this index was the same in both groups.

Results

Among patients with normal hearts and idiopathic dilated cardiomyopathy, the index of proportionality between the two segments (septal and non-septal) showed no significant difference in the three regions analyzed. The comparison results of the indices NSS/SS among normal and enlarged hearts were respectively: in base 1.99 versus 1.86 (P=0.46), in equator 2.22 versus 2.18 (P=0.79) and in apex 2.96 versus 3.56 (P=0.11).

Conclusion

In the idiopathic dilated cardiomyopathy, the transversal dilatation of left ventricular internal perimeter occurs proportionally between the segments corresponding to the septum and free wall at the basal, equatorial and apical regions of this chamber.

Partial left ventriculectomy and mitral valve repair: favorable short-term results in carefully selected patients with advanced heart failure due to dilated cardiomyopathy

BACKGROUND

Because of the scarcity of donor hearts, surgical alternatives to heart transplantation, such as partial left ventriculectomy (PLV), were introduced for treatment of advanced heart failure. Here, we report our experience with this procedure performed in combination with mitral valve repair.

METHODS

Twelve patients with dilated cardiomyopathy (DCM), New York Heart Association (NYHA) class exceeding III on maximal medical therapy, cardiac index of 2.5 liter/min/m2 or less, VO2max of 14 ml/kg/min or less, left ventricular end-diastolic diameter (LVEDD) of 7.0 cm or more, and grade II or greater mitral incompetence, were selected for PLV and mitral valve reconstruction (MVR). Echocardiography, hemodynamics, spiroergometry, and clinical assessment were performed before and 1 year after the operation.

RESULTS

One-year survival was 83.3%. All 10 surviving patients were free from failure of the procedure 1 year post-operatively. From pre-operatively to 1 year post-operatively, NYHA functional class improved from 3.3 +/- 0.3 to 1.9 +/- 0.2 (p < 0.001), cardiac index increased from 2.0 +/- 0.2 liter/min/m2 to 2.9 +/- 0.2 liter/min/m2 (p < 0.001), stroke volume index from 25.9 +/- 4.8 ml/m2 to 40.3 +/- 7.3 ml/m2 (p = 0.008), and VO2max from 10.9 +/- 2.4 ml/kg/min to 16.0 +/- 3.6 ml/kg/min (p = 0.016), whereas LVEDD decreased from 8.4 +/- 0.6 cm to 6.6 +/- 0.3 cm (p < 0.001), left ventricular end-systolic diameter from 6.8 +/- 0.8 cm to 5.3 +/- 0.5 cm (p < 0.001), and mitral incompetence from 2.4 +/- 0.6 to 0.9 +/- 0.6 (p < 0.001). Pulmonary pressures and fractional shortening did not change significantly (p > 0.05). Four patients received an implantable cardioverter/defibrillator as a result of their pathologic electrophysiologic examination.

CONCLUSIONS

In carefully selected patients, PLV combined with MVR achieves short-term results comparable to that after heart transplantation. However, long-term results and multicenter evaluation will be needed to define its place in the treatment of advanced heart failure.

Partial left ventriculectomy in modified adriamycin-induced cardiomyopathy in the dog

BACKGROUND

The purpose of this study was to evaluate modified adriamycin-induced cardiomyopathy in the dog for research on partial left ventriculectomy (PLV).

METHODS

An intracoronary catheter was introduced into the left main stem via the first marginal branch in a retrograde fashion in 12 adult foxhound dogs. The catheter was connected to a percutaneous access port that was used for weekly adriamycin administration (10 mg over a 1-hour period on 5 occasions). Follow-up examinations (transthoracic echocardiography, hemodynamic parameters, cardiopulmonary status, neurohormones) were done before, 1 week after the last adriamycin administration, and then 6 weeks later. This protocol was performed in 6 dogs (control group: Group 1). The other 6 dogs underwent PLV 1 week after the last adriamycin administration (Group 2). After the last measurements, all dogs were killed with saturated potassium chloride under general anesthesia and the hearts were excised for histologic examination. All data were calculated as mean and standard error of the mean. Differences were calculated by the Wilcoxon signed-rank test for paired and unpaired data. p < 0.05 was considered statistically significant.

RESULTS

One dog from each group died suddenly during adriamycin administration (probably due to ventricular arrhythmia). In addition, 1 dog from Group 2 suffered from a severe systemic inflammatory response syndrome after PLV and died 36 hours after surgery. Thus, 5 dogs from Group 1 and 4 from Group 2 underwent the entire study protocol. Adriamycin administration resulted in a severe dilated cardiomyopathy that was comparable in both groups (significant increase of central venous pressure, mean pulmonary artery pressure, pulmonary wedge pressure, left ventricular end-systolic and end-diastolic diameters, oxygen extraction, troponin I and anti-diuretic hormone, whereas cardiac output, ejection fraction and venous oxygen saturation decreased significantly). Deterioration of cardiac function continued after termination of adriamycin administration in Group 1 dogs, albeit not as progressively as during adriamycin administration. In contrast, cardiac function improved in Group 2 dogs after PLV, but did not reach baseline values. Cardiac index increased and oxygen extraction (p = 0.03) decreased, resulting in an enhanced venous oxygen saturation (p = 0.02). In particular, the distance of the papillary muscles at end diastole (p = 0.02) and at end systole (p = 0.02) at the mid-papillary level decreased significantly after PLV, resulting in reduced left ventricular diameter and volume (statistically significant for left ventricular end-systolic diameter and volume). All hearts had severe histologic alterations characteristic of adriamycin-induced toxicity, including cytoplasmic vacuolation, myocyte degeneration and increased fibrosis.

CONCLUSION

Modified adriamycin-induced cardiomyopathy in the dog may be suitable for research on PLV.