Paradoxical Septal Motion after Uncomplicated Cardiac Surgery: A Consequence of Altered Regional Right Ventricular Contractile Patterns

Paroxysmal interventricular septal motion (PSM) is the movement of the septum toward the right ventricle (RV) during cardiac systole. It occurs frequently after uncomplicated cardiac surgery (CS), including coronary bypass (on-pump and off-pump), valve repair or replacement, and with all types of incisions (sternotomy or mini-thoracotomy). It sometimes resolves quickly but may persist for months or become permanent. Global RV systolic function, stroke volume and ejection fraction remain normal after uncomplicated CS, but regional contractile patterns are altered. There is a decrease in longitudinal shortening but an increase in transverse shortening in the endocardial and epicardial right ventricular muscle fibers, respectively. PSM is a secondary event as there is no loss of septal perfusion or thickening. The increased RV transverse shortening (free wall to septal fibers) may modify septal movement resulting in PSM that compensates for the reduced RV longitudinal shortening, thus preserving normal global right ventricular function.

Cardioplegia strategies

There are many cardioplegic strategies for coronary surgery. The goal is a dry operative field while maximizing myocardial recovery. Prospective randomized clinical trials have historically been difficult to achieve because of confounding variables such as solution used, route of administration, temperature, and so forth. This chapter describes an ‘integrated method’ of cardioplegia, so named because it combines many of the salient feature of various methods. It is designed to provide the maximum metabolic support of the myocardium during each phase of the operation. A vast literature from the laboratory to the bedside supports its use. Perhaps most importantly, integrated cardioplegia provides excellent protection of the septum and avoids paradoxical septal motion that may be a form of myocardial injury which is common with other methods of myocardial protection. Any future evaluation of cardioplegia methods should include not only survival but enzyme release and echocardiographic measurements of septal function.

Impact of pectus excavatum on cardiac morphology and function according to the site of maximum compression: effect of physical exertion and respiratory cycle

Aims Previous studies have demonstrated diverse cardiac manifestations in patients with pectus excavatum (PEX), although mostly addressing morphological or physiological impact as separate findings. Using multimodality imaging, we evaluated the impact of PEX on cardiac morphology and function according to the site of maximum compression, and the effect of exertion and breathing. Methods and results All patients underwent chest computed tomography, cardiac magnetic resonance (CMR), and stress echocardiography (echo) in order to establish surgical candidacy. We evaluated diastolic function and trans-tricuspid gradient during stress (echo); and systolic function and respiratory-related septal wall motion abnormalities (CMR). Patients were classified according to the site of cardiac compression as type 0 (without cardiac compression); type 1 (right ventricle); and type 2 [right ventricle and atrioventricular (AV) groove]. Fifty-nine patients underwent multimodality imaging, with a mean age of 19.5 ± 5.9 years. Compared with a sex and age matched control group, peak exercise capacity was lower in patients with PEX (8.4 ± 2.0 METs vs. 15.1 ± 4.6 METs, P < 0.0001). At stress, significant differences were found between groups regarding left ventricular E/A (P = 0.004) and e/a ratio (P = 0.005), right ventricular E/A ratio (P = 0.03), and trans-tricuspid gradient (P = 0.001). At CMR, only 9 (15%) patients with PEX had normal septal motion, whereas 17 (29%) had septal flattening during inspiration. Septal motion abnormalities were significantly related to the cardiac compression classification (P < 0.0001). Conclusions The present study demonstrated that patients with PEX, particularly those with compression affecting the right ventricle and AV groove, manifest diverse cardiac abnormalities that are mostly related to exertion, inspiration, and diastolic function.

Secundum Atrial Septal Defect Before and After Surgery

Twenty patients with secundum atrial septal defect, who had undergone open heart surgery were studied retrospectively. Girls were more affected than boys; the sex ratio was 1.5 : I. Associated cardiac defects were diagnosed in two patients, one with moderate valvular pulmonic stenosis and the other one with small ventricular septal defect. Typical clinical findings consisted of loud first heart sound, widely fixed split second heart sound and soft ejection systolic murmur at the upper left sternal border were heard in all cases. Mid diastolic murmur due to relative tricuspid stenosis was detected in most cases (75%). Electrocardiographic findings included right axis deviation, prolonged PR-interval and right atrial enlargement were found in 50%, 15% and 60% of cases, respectively. Incomplete right bundle branch block and right ventricular enlargement were found in all cases, as was cardiomegaly with increased vascular markings were found in all cases. Paradoxical ventricular septal motion and visualization of the atrial septal defect were seen in 95% and 75% of cases, respectively. Cardiac catheterization was performed in 19 patients (95%). The pulmonary-systemic flow ratio (Qp/Qs) ranged from 1.7 to 6.3 (mean 2.9 ± 0.67), and was correlated to the presence of mid diastolic tricuspid flow murmur and paradoxical ventricular septal motion. Simple closure of the defect was the procedure of choice, but in one patient (5%) pericardial patch was used to close the very large defect. The mortality rate was 10 percent. Physical retardation was found in all boys and 50% of girls, before surgery. Body weight percentile increased in most cases (61.1 %), while body height percentile increased in only 5.6% of cases, postoperatively. Ejection systolic murmur at the upper left sternal border was still detected in one patient (5.6%). lncomplele right bundle branch block persisted in all cases, while cardiomegaly was still found in 5. 6% of cases followed up six months to five years after surgery. There was no residual left ventricular dysfunction in all cases.