Surgical treatment of post-infarction left ventricular pseudoaneurysm: Case series highlighting various surgical strategies.

INTRODUCTION AND OBJECTIVE: The left ventricular pseudoaneurysm (LVP) is rare, the surgical experience is limited and its surgical treatment remains still a challenge with an elevated mortality. Herein, it is presented a retrospective analysis of our experience with acquired post infarct LVP over a10-year period. MATERIALS AND METHODS: Between January 2006 through August 2016, a total of 13 patients underwent operation for post infarct pseudoaneurysm of the left ventricle. There were 10 men and 3 women and the mean age was 61 ± 7.6 years. 4 patients presented acute LVP. Two patients had preoperative intraortic balloon pump implantation. RESULTS: Various surgical techniques were used to obliterate the pseudoaneurysm such as direct pledgeted sutures buttressed by polytetrafluoroethylene felt, a Gore-Tex or Dacron patch, transatrial closure of LVP neck in submitral pseudoaneurysm, or linear closure in cases presenting associated postinfarct ventricular septal defect. Concomitant coronary artery bypasses were performed for significant stenoses in 12 patients, ventricular septal defect closure in 4 patients, mitral valve replacement in 3 and aortic valve replacement in 1 patient. Operative mortality was 30.8% (4 patients). Three of them were acute LVP. Three patients required the continuous hemodyalisis and 8 patients required intra-aortic balloon pump. At follow-up two deaths occurred at 1 and 3 years after surgery. CONCLUSION: In conclusion, this study revealed that surgical repair of post infarct left ventricular pseudoaneurysm was associated with an acceptable surgical mortality rate, that cardiac rupture did not occur in surgically treated patients.

Early and mid-term outcome in terms of functional and hemodynamic performance of the st. Jude regent 19-mm aortic mechanical prosthesis versus 19-mm carpentier edwards aortic biological prosthesis.

BACKGROUND: The aim of the present study is to compare the early and mid-term clinical and hemodynamic results of the aortic valve replacement (AVR) with a St Jude Medical Regent 19-mm prosthesis (SJMR-19) versus Carpentied-Edwars bovine pericardial 19-mm valve (CE-19). METHODS: Between January 2002 and January 2012, 265 patients (Group I) and 58 patients (Group II) with underwent AVR with a SJMR-19 and CE-19 respectively. There were no significant differences between groups regarding the demographic and preoperative echocardiographic data. Thirty-six patients in Group I and 4 in Group II required annulus enlargement in association or not with septal myectomy. The mean follow-up was 34 ± 18.5 months (range 5-60 months). RESULTS: There were 14 (5.3 %) hospital deaths in Group I versus 4 (6.8 %) in Group II (p = 0.86). The multivariate logistic regression analysis identified the LVEF ≤ 35 % (p = 0.001), combined operation (p = 0.0005), CPB (p = 0.033), age (p = 0.011), annulus enlargement (p = 0.0009), reoperation (p = 0.039) and chronic renal failure (p = 0.011) as strong predictors for early postoperative death. Within 1 year after surgery peak pulmonary artery pressure, interventricular septal and left ventricular posterior wall thickness decreased significantly in both groups. The M-TPG was 15.7 ± 6.5 mmHg in Group I versus 17 ± 7 mmHg in Group II (p = 0.19). The multivariate regression analysis revealed the annulus enlargement (p = 0.018), small EOAi (p = 0.00004), postoperative LVMi (p = 0.0001) and BSA (p = 0.019) as strong predictors for higher M-TPG. The postoperative LVMi was 119 ± 22.5 gm/m(2) in Group I and 122 ± 22 gm/m(2) in Group II (p = 0.37), significantly lower than the respective preoperative values 162.5 ± 34 gm/m(2) (Group I) and 168 ± 30 gm/m(2) (Group II). The actuarial survival and cumulative free-reoperation actuarial survival at 5 years follow-up were 96.7 and 94.5 % respectively in Group I and 97 and 91 % in Group II.. There were non significant differences between groups regarding the actuarial survival and cumulative free-reoperation survival. The Cox model identified the older age (p = 0.022), LVEF ≤ 35 % (p = 0.009), reoperation (p = 0.018), combined surgery (p = 0.00075) and annulus enlargement (p = 0.033) as strong predictors for poor actuarial free-reoperation survival. CONCLUSIONS: Both the SJMR-19 and CE-19 offers excellent postoperative clinical and hemodynamic outcome in patients with small aortic annulus. The LV hypertrophy and transvalvular gradients are reduced significantly indenpendently of the employed SJMR-19 or CE-19 prosthesis. Our data support recent suggestions that small valve size does not influence intermediate free-reoperation survival. The CE-19 is an excellent alternative to SJMR-19 in old patients.

Does the St. Jude Regent 17-mm Offer Better Outcomes Than the Hemodynamic Plus 17-mm Aortic Valve Mechanical Prothesis?

OBJECTIVE: The aim of the present study is to report the early and mid-term clinical and hemodynamic results of a prospective trial investigating the clinical performance of the St. Jude Medical Regent 17 mm (SJMR-17) versus St. Jude Medical Hemodynamic Plus 17 mm (SJMHP-17). MATERIALS AND METHODS: Between January 2000 and August 2013, 20 patients (Group I) with aortic valve (AV) stenosis underwent first time AV replacement with a SJMR-17 and nine patients (Group II) underwent AV replacement with a SJMHP-17. The mean follow-up was 58 ± 31 months. RESULTS: There was one death in Group I. The end-diastolic IVS thickness and end-systolic posterior left ventricle (LV) wall thickness was reduced significantly in boths groups (p = 0.001 and p = 0.006 in Group I and p = 0.007 and p = 0.011 in Group II). The peak and mean transprosthesis gradients (P-TPG and M-TPG) were 29 ± 6.8 mmHg and 17.5 ± 4.5 mmHg in Group I, significantly lower than in Group II (55.2 ± 19.7 mmHg and 28.8 ± 7.7 mmHg). The postoperative left ventricular mass (LVM) and indexed left ventricular mass (LVMi) were reduced significantly in both groups versus the preoperative values. The postoperative LVMi was 114.5 ± 10.6 g/m(2) in Group I versus 127 ± 8 g/m(2) in Group II (p = 0.01). With dobutamine, heart rate, left ventricular ejection fraction, cardiac output, transprosthesis peak, and mean gradients increased significantly in both groups, however, the P-TPG and M-TPG were significantly higher in Group II (p = 0.026 and p = 0.022) despite a non-significant increase of the indexed effective orifice area. CONCLUSIONS: The SJMR-17 can be employed with satisfactory postoperative clinical and hemodynamic outcomes in patients with small aortic annulus, especially in elderly patients offering better outcome than SJMHP-17.

Hemodynamics of 17-mm vs. 19-mm St. Jude Medical Regent and annulus enlargement.

OBJECTIVE: We aimed to compare early and midterm clinical and hemodynamic outcomes of 17-mm vs. 19-mm St. Jude Medical Regent valves with concomitant aortic annulus enlargement. METHODS: Between 1999 and 2012, 20 patients (group 1) underwent first-time aortic valve replacement with a 17-mm St. Jude Medical Regent valve, and 35 patients (group 2) had a 19-mm valve and concomitant aortic annulus enlargement. The mean follow-up was 81 ± 37 months (range 20-110 months). RESULTS: There was one death in group 1 vs. 4 in group 2 (p > 0.05). The mean postoperative transprosthetic gradient was 17.5 ± 4.5 in group 1 and 17 ± 6.4 mm Hg in group 2 (p = 0.83), and 37 ± 10.7 and 32 ± 13 mm Hg, respectively, under stress (p = 0.17). Left ventricular mass and left ventricular mass index were reduced and similar in both groups. Postoperative effective orifice area index was higher in group 2 (0.85 ± 0.17 cm(2 )m(-2)) than group 1 (0.76 ± 0.2 cm(2 )m(-2); p > 0.05). A multivariate Cox model identified a 19-mm valve with aortic annulus enlargement (p = 0.032), functional class (p = 0.025), reoperation (p = 0.04), ejection fraction < 35% (p = 0.042), and combined surgery (p = 0.04) as strong predictors of poorer overall event-free survival. CONCLUSIONS: The 17-mm St. Jude Medical Regent valve may be employed with satisfactory postoperative clinical and hemodynamic outcomes in patients with a small aortic annulus, as an alternative to a larger prothesis with aortic annulus enlargement.

Early and mid-term functional and hemodynamic evaluation of the St. Jude Medical Regent 17 mm aortic valve mechanical prosthesis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to report the early and mid-term clinical and hemodynamic results of a prospective trial investigating the clinical performance of the St. Jude Medical Regent 17 mm mechanical aortic valve prosthesis (SJMR-17). METHODS: Between January 2001 and January 2009, 20 patients (18 females, two males; mean age 69.2 +/- 7.3 years) with aortic valve stenosis underwent first-time aortic valve replacement (AVR) with the SJMR-17. The mean body surface area (BSA) was 1.68 +/- 0.2 m2, and the mean follow up was 18.7 +/- 9.2 months (range: 10-32 months). All patients were monitored with serial echocardiography; the first study was performed preoperatively, while subsequent controls were at two and six months, and within one year, respectively. All survivors underwent dobutamine stress testing (DSE) at one year after surgery. RESULTS: There was one death. At the six-month follow up the mean NYHA class was 1.3 +/- 0.6, and was significantly lower than preoperatively 2.75 +/- 0.86 (p < 0.0001). The peak and mean transprosthetic gradient (TPG) was 29 +/- 6.8 and 17.5 +/- 4.5 mmHg respectively, significantly lower than preoperatively. The left ventricular mass (LVM; g) and indexed left ventricular mass (LVMi; g/m2) were 191.0 +/- 22.6 g and 114.5 +/- 10.6 g/m2, respectively, and were significantly lower than preoperative values (258.0 +/- 40.0 g, p < 0.0001; and 157.0 +/- 26.0 g/m2, p = 0.00002). The mean TPG correlated well with the LVMi reduction (p = 0.033). During DSE, the peak and mean TPGs were increased significantly to 73.8 +/- 17.7 mmHg and 37 +/- 10.7 mmHg, respectively, significantly higher than at the basal (resting) state. Multivariate regression analysis identified the effective orifice area index, BSA, age and postoperative LVMi as strong predictors for a higher mean TPG. CONCLUSION: The SJMR-17 prosthesis might be employed with satisfactory postoperative clinical and hemodynamic outcome in patients with a small aortic annulus, especially in elderly patients, as an alternative to other valves, or to other surgical strategies such as annulus enlargement.

Surgical outcome of reoperation due to left atrioventricular valve regurgitation after previous correction of complete atrioventricular septal defect.

OBJECTIVES: The aims of this study were to evaluate the early and late outcomes in patients undergoing reoperation due to left atrioventricular valve regurgitation (LAVVR) after initial complete repair (ICR) of complete atrioventricular septal defect (CAVSD). MATERIALS AND METHOD: Between January 1990 and April 2013, 45 consecutive patients underwent reoperation due to severe LAVVR. The mean age was 7.5 ± 6.2 years. Associated LAVV malformations were found in 22 (49%) patients and associated cardiac malformations in 18 (40%). The mean follow-up was 6.8 ± 2.6 years. RESULTS: LAVV repair was possible in all patients. There were two hospital deaths (4.5%). Ten patients (22%) required a second reoperation due to severe LAVVR at mean 7.5 ± 8.4 months after the first reoperation. The actuarial overall survival and free-reoperation survival rates at one, three, and five years were 95.4%, 92.8%, and 92.8% and 89%, 80.5%, and 72%, respectively. Multivariate analysis revealed that the associated cardiac malformations, LAVV leaflet prolapse or detachment from the septal patch, associated LAVV malformations, and post-first correction LAVVR grade ≥ 2 were strong predictors for poor overall free-reoperation survival in patients undergoing reoperation due to LAVVR after ICR of various forms of ACVSD. CONCLUSIONS: Patients with severe LAVVR post-ICR of CAVSD may undergo reoperation with acceptable postoperative mortality and morbidity; however, they are at an increased risk for developing postoperative LAVVR and subsequent reoperation.

Chronic atrial fibrillation alters the functional properties of If in the human atrium.

INTRODUCTION: Despite the evidence that the hyperpolarization-activated current (If) is highly modulated in human cardiomyopathies, no definite data exist in chronic atrial fibrillation (cAF). We investigated the expression, function, and modulation of If in human cAF. METHODS AND RESULTS: Right atrial samples were obtained from sinus rhythm (SR, n = 49) or cAF (duration >1 year, n = 31) patients undergoing corrective cardiac surgery. Among f-channel isoforms expressed in the human atrium (HCN1, 2 and 4), HCN4 mRNA levels measured by RT-PCR were significantly reduced. However, protein expression was preserved in cAF compared to SR (+85% for HCN4); concurrently, miR-1 expression was significantly reduced. In patch-clamped atrial myocytes, current-specific conductance (gf) was significantly increased in cAF at voltages around the threshold for If activation (-60 to -80 mV); accordingly, a 10-mV rightward shift of the activation curve occurred (P < 0.01). ß-Adrenergic and 5-HT4 receptor stimulation exerted similar effects on If in cAF and SR cells, while the ANP-mediated effect was significantly reduced (P < 0.02), suggesting downregulation of natriuretic peptide signaling. CONCLUSIONS: In human cAF modifications in transcriptional and posttranscriptional mechanisms of HCN channels occur, associated with a slight yet significant gain-of-function of If , which may contribute to enhanced atrial ectopy.

Isolated papillary muscle rupture complicating acute pancreatitis.

Papillary muscle rupture in the absence of coronary stenoses is a rare event. An isolated infarction of the papillary muscle is involved in most cases, but the pathogenesis is still debated. We describe an anterolateral papillary muscle rupture complicating acute pancreatitis in a patient without significant coronary stenoses and with evidence of coronary spasm. This suggests that an increased susceptibility to coronary spasm and thrombosis, triggered by an acute systemic inflammatory response, may represent a mechanism of selective papillary muscle infarction.

Electrophysiological characterization of isolated human atrial myocytes exposed to tegaserod.

Tegaserod (Teg), a 5-hydroxytryptamine type-4 (5-HT(4)) receptor partial agonist, represents a novel treatment for irritable bowel syndrome with constipation and chronic constipation. Cardiovascular safety data from pooled clinical studies showed a signal suggestive of increased occurrence of ischaemic cardiovascular events in patients exposed to Teg versus placebo. Thereafter, marketing of Teg was suspended in the USA and other countries. The clinical data did not demonstrate a causative effect but raised questions of whether a non-recognized effect on the heart was present. Our aim was to evaluate for arrhythmogenic potential of Teg on human cardiomyocytes. Cells isolated from human atrial specimens during cardiac surgery were used to assess the effects of Teg (1, 10, 30 and 100 nM) on action potential and I(f) (funny current) by patch-clamp technique. Results showed that Teg (at all concentrations tested) did not significantly affect action potential characteristics of atrial myocytes when driven at different rates (0.2, 0.5 and 1 Hz). In contrast, 5HT significantly prolonged action potential duration (1 and 10 nM) and caused cell un-excitability (100 nM). Teg, at the highest concentration tested (100 nM, corresponding to 10 times C(max), produced by the recommended dose of 6 mg b.i.d.) increased the I(f) amplitude and caused a shift of its activation curve. This effect of a high concentration of Teg is not considered clinically relevant. When evaluated on single human atrial cells, Teg does not appear to exhibit arrhythmogenic properties, as it did not affect the action potential profile.

Totally endoscopic subxiphoid pericardioscopy: early steps with a new surgical tool.

BACKGROUND: Pericardial pathology still has challenging diagnostic and treating issues. To reduce surgical trauma and pain for the patient, the authors developed a totally endoscopic echo-guided approach for both diagnostic and operative pericardioscopy. METHODS: Three steps moved from animal model (8 pigs) through concomitant open-chest interventions (7 patients) to closed-chest interventions for 10 patients with a diagnosis of severe pericardial effusion. RESULTS: A lesion of the right ventricle in one patient (10%) due to imperfect preoperative pericardial visualization needed sternotomy for repair. All the patients, except the aforementioned one, underwent surgery with local anesthesia or mild sedation. No method-related mortality was reported. CONCLUSION: The closed-chest nonintrapleural approach to the pericardium may represent an evolution, with a positive impact on the treatment of this pathology. Therapeutic maneuvers with rigid instruments in nonintubated patients are possible. Accurate patient selection and technical refinement should increase the safety and effectiveness of the method.

Tension generation and relaxation in single myofibrils from human atrial and ventricular myocardium.

Fast solution switching techniques in single myofibrils offer the opportunity to dissect and directly examine the sarcomeric mechanisms responsible for force generation and relaxation. The feasibility of this approach is tested here in human cardiac myofibrils isolated from small samples of atrial and ventricular tissue. At sarcomere lengths between 2.0 and 2.3 mum, resting tensions were significantly higher in ventricular than in atrial myofibrils. The rate constant of active tension generation after maximal Ca(2+) activation (k (ACT)) was markedly faster in atrial than in ventricular myofibrils. In both myofibril types k (ACT) was the same as the rate of tension redevelopment after mechanical perturbations and decreased significantly by decreasing [Ca(2+)] in the activating solution. Upon sudden Ca(2+) removal, active tension fully relaxed. Relaxation kinetics were (1) much faster in atrial than in ventricular myofibrils, (2) unaffected by bepridil, a drug that increases the affinity of troponin for Ca(2+), and (3) strongly accelerated by small increases in inorganic phosphate concentration. The results indicate that myofibril tension activation and relaxation rates reflect apparent cross-bridge kinetics and their Ca(2+) regulation rather than the rates at which thin filaments are switched on or off by Ca(2+) binding or removal. Myofibrils from human hearts retain intact mechanisms for contraction regulation and tension generation and represent a viable experimental model to investigate function and dysfunction of human cardiac sarcomeres.

Perioperative and clinical-angiographic late outcome of total arterial myocardial revascularization according to different composite original graft techniques.

Total arterial myocardial revascularization (TAMR) is advisable because of the excellent long-term patency of arterial conduits. We present early and midterm outcomes of five different surgical configurations for TAMR. Between January 1998 and May 2004, 112 patients (aged 56.5 +/- 4.5 years, 20% female) with three-vessel disease underwent TAMR. The internal mammary arteries (IMAs) were harvested in a sketelonized fashion. The surgical techniques for TAMR consisted in Y or T composite grafts (n = 88, 78%) constructed between the in situ right IMA (RIMA) and the free left IMA (LIMA) graft (n = 58) or the radial artery (n = 30) (RA) in three different configurations. The other techniques consisted in T- and inverted T-graft (n = 24, 22%) constructed between the RA conduit and the free LIMA graft in two different configurations. The mean follow-up time was 40 +/- 23 months. Postoperative angiographic control was performed in 76/111 (70%) patients. Overall, 472 arterial anastomoses (average 4.2 per patient) were performed. One (0.9%) patient, undergoing the inverted T-graft technique, died on postoperative day 2. Another patient (0.9%), undergoing the lambda-graft technique using both IMAs and RA, suffered a new myocardial infarction probably due to RA conduit vasospasm. One week after surgery, after the transthoracic echocardiographic Doppler with adenosine provocative test, the coronary flow reserve (CFR) at the LIMA and RIMA main stems were 2 +/- 0.4 and 2.4 +/- 0.3, respectively. At 12-month follow-up, after adenosine provocative test, the CFRs at the LIMA and RIMA stems were significantly higher than the values at 1 week after surgery within the same group; (LIMA)CFR (1 week) 2.4 +/- 0.3 (12 months) vs 2 +/- 04 (1 week), P = 0.002; (RIMA)CFR 2.58 +/- 0.4 vs 2.4 +/- 0.3, P = 0.001. The CFR at the RIMA main stem was higher in all measurements within the same group than in the LIMA main stem, but not significantly. In one patient undergoing the lambda-graft technique using both IMAs, the RIMA was found to have a string sign. Postoperative angiography in 50 patients showed that the patency rate for the LIMA was 100%, for the RIMA 97.3%, and for the RA 96.7%. Angiography at 3-year follow-up in 76 patients documented excellent patency rates of the LIMA (97.4%), RIMA (95%), and RA (87%). Survival at 7 years was 92.5%, event-free survival 89.3%, and freedom from angina 94%. Total arterial myocardial revascularization using different surgical configurations is safe and effective. The use of composite arterial grafts provides excellent clinical and angiographic results, with a low rate of angina recurrence and late cardiac events. These configurations allow for complete arterial revascularization.

Skeletonized bilateral internal mammary arteries for non-elective surgical revascularization in unstable angina.

OBJECTIVE: The aim of this study was to evaluate the feasibility, safety and outcome of skeletonized bilateral internal mammary arteries (BIMA) in patients with unstable angina (UA) undergoing non-elective myocardial revascularization. METHODS: Between January 1997 and December 2003, 758 patients, mean age 62+/-12 years, underwent non-elective coronary artery bypass grafting (CABG) for unstable angina. Two hundred and five (27%) were operated emergently and 503 (73%) urgently. BIMA were employed in 320 (42%) patients (Group B) and isolated left IMA and/or saphenous vein grafts in the remaining 438 (58%) patients (Group M). RESULTS: In-hospital mortality (B = 5.9% and M = 5.3%), and perioperative myocardial infarction (B = 2.2%; M = 1.96%) were similar between the two groups (P = ns). Actuarial survival at 1, 3 and 7 years was 98.7, 97.5 and 96.2% in B and 99, 94.3 and 88.4% in M (P < 0.05 at 7 years follow-up). At 7 years follow-up, the event-free cardiac survival (92 vs. 87%, P = 0.021), angina-free survival (98.6 vs. 94%, P = 0.039), reoperation-free cardiac survival (98 vs. 95%, P = 0.04) and infarct-free cardiac survival (98.7 vs. 96%, P = 0.05) were better in Group B. Multivariate analysis identified age > 65 years (P = 0.02), LVEF < 35% (P = 0.01), > 1 ischemic irreversible area (P = 0.03) as independent predictors for late deaths, while the use of the LIMA (P=0.006) and both mammary arteries (P=0.001) decreased the risk of late deaths. CONCLUSIONS: The use of BIMA in non-elective CABG for UA is safe and effective. Mid-term outcome, however, are superior with improved freedom from cardiac death, from coronary reintervention and from myocardial infarction.

Pharmacological modulation of the hyperpolarization-activated current (I f) in human atrial myocytes: focus on G protein-coupled receptors.

AIMS: In human atrial myocytes (HuAM) two beta-adrenergic receptors (beta-AR) and four splicing-variants of the serotonin 5-HT(4) receptor are present. Multiple coupling with G stimulatory (G(s)) and G inhibitory (G(i)) proteins has been proposed for both beta(2)-AR and 5-HT((4b)) subtypes, but no functional data exist in HuAM. Serotonin (5-HT) and catecholamines are able to trigger arrhythmias in human atrium, but the underlying cellular mechanisms are not completely understood. The pacemaker current (I(f)) is an inward Na(+)/K(+) current, constitutively present in HuAM and directly modulated by cAMP; I(f) could play a role in triggering human atrial arrhythmias. This study evaluated the different G protein coupling of beta(1)-AR, beta(2)-AR and 5-HT(4) receptors by assessing the modulation of I(f) by selective stimuli. METHODS: HuAM were isolated from right atrial appendages and utilized for patch-clamp recording. The coupling of receptor subtypes with G(i) proteins was tested by incubating HuAM in pertussis toxin (PTX). RESULTS: Beta(1)-AR stimulation (Isoprenaline [ISO] + ICI 118,551), and 5-HT caused a concentration-dependent significant shift of the half activation potential of I(f) activation curve (DeltaV(h)), P < 0.01. beta(2)-AR stimulation (ISO 1 microM + CGP 20712A) also significantly shifted V(h) (P < 0.0001), but with DeltaV(h)[beta(2)-AR] significantly smaller than the effect caused by 1 microM beta(1)-AR stimulation (P < 0.05). Pre-treatment of HuAM with PTX did not alter the effect of beta(1)-AR stimulation (both 0.1 and 1 microM) and 1 microM 5-HT on I(f), but significantly increased the effect in response to beta(2)-AR stimulation and 0.1 microM 5-HT (P < 0.05 for both), thus suggesting a G(i) protein coupling of these receptors. CONCLUSIONS: Our results provide the first functional evidence of the different G protein coupling of beta(1)-AR, beta(2)-AR and 5-HT(4) receptors in HuAM. Further they support the view that I(f) current might play an important role in triggering catecholamines and serotonin-induced atrial arrhythmias.

Surgical revascularization of coronary bifurcations employing a single arterial graft according to the "omega-anastomosis" technique: initial experience.

OBJECTIVES: The aim of this study was to evaluate the early postoperative outcome in patients undergoing "omega-anastomosis" construction, a technique that permits revascularization of coronary bifurcations employing a single arterial graft. MATERIALS AND METHODS: Between January 2000 and March 2002, omega-anastomosis was employed in 12 patients. The main indication for omega-anastomosis construction was the presence of a significant stenotic lesion involving one of the coronary tree's bifurcations, presenting a relevant secondary branch. There were ten men and two women, with a mean age of 55.4 +/- 4.3 years (range 48 to 66). The omega-anastomosis was constructed employing a single arterial graft (internal mammary artery or radial artery) effectively tailored to obtain a bi-petal shape and anastomosed to the coronary bifurcation according to a three-foliate anastomosis. All patients underwent postoperative coronary angiography. RESULTS: There were no hospital deaths, neither ECG nor enzymatic alterations. One patient was reoperated for excessive bleeding. The mean aortic cross-clamp time and duration of CPB (cardiopulmonary bypass) were 64 +/- 18 minutes (range 45 to 108) and 89 +/- 26 minutes (range 67 to 135), respectively. Thirty-four arterial conduits were used: 12 LIMA, 12 RIMA, and 10 RA. Twelve omega-anastomoses were constructed, in six patients employing the RA, and in six other patients employing one of the internal mammary arteries (IMAs). Five left Y-grafts between the in situ LIMA and free LIMA graft and one right Y-graft between the RIMA and RA were constructed. The mean ICU stay was 14.4 +/- 5.7 hours. The postoperative coronary angiography revealed a good patency of the "omega-anastomosis." Transthoracic color Doppler echocardiography (TTECD) demonstrated a normal IMAs flow pattern in all cases. CONCLUSIONS: We define the reported configuration as a possible surgical alternative to achieve total arterial myocardial revascularization in multi-vessels patients, associated with excellent postoperative outcome that should be part of the coronary surgical armamentarium.

Atrial natriuretic peptide modulates the hyperpolarization-activated current (If) in human atrial myocytes.

OBJECTIVES: The relationship between atrial stretching and changes in cell excitability is well documented. Once stretched, human atrial myocytes (HuAM) release atrial natriuretic peptide (hANP). Receptors for hANP (NPR) are coupled to a guanylyl cyclase (GC) activity, and are present on HuAM, but the electrophysiological effects of hANP are largely unknown. We investigated the effect of hANP on If, the hyperpolarization-activated current present in HuAM, and the underlying intracellular pathway. METHODS: HuAM were isolated from atrial appendages and utilized for patch-clamp recording. RESULTS: hANP caused a significant and concentration dependent shift of the midpoint activation potential (DeltaVh) toward less negative potentials of 6.9 +/- 1.0 mV at 0.1 nM; 13.0 +/- 2.6 mV at 1 nM and 15.3 +/- 2.2 mV at 10 nM (p < 0.001 for all); a parallel increase of If rate of activation occurred. The effect of hANP was completely blocked by isatin, a potent antagonist of NPR (p < 0.01 vs. hANP). In the presence of the inhibitors of guanylyl cyclase (ODQ and LY83583), hANP caused a significantly smaller DeltaVh (p < 0.01 vs. hANP for both). 8Br-cGMP mimicked the effect of hANP, both in the presence and absence of KT5823, a selective inhibitor of Protein kinase G. Pretreatment with pertussis toxin (PTX) did not change the effect of hANP, thus excluding a major role for the coupling of NPR with the Gi-Proteins system. Pretreating cells with cyclopentyladenosine (CPA), an A1-adenosine receptor agonist, completely blocked hANP effect. Adding hANP to maximal serotonin concentration produced an additive response. CONCLUSIONS: Our data demonstrate for the first time that ANP is able to increase If, likely through a modulation of intracellular cGMP and cAMP levels. This effect could have implications in the relationship between stretch and arrhythmogenesis in the human atrium.

Beating heart ischemic mitral valve repair and coronary revascularization in patients with impaired left ventricular function.

OBJECTIVE: The aim of this study is to evaluate in a cohort of patients with impaired left ventricular (LV) function and ischemic mitral valve regurgitation (MVR), the effects of on-pump/beating heart versus conventional surgery in terms of postoperative mortality and morbidity and LV function improvement. MATERIALS AND METHODS: Between January 1993 and February 2001, 91 patients with LVEF between 17% and 35% and chronic ischemic MVR (grade III-IV), underwent MV repair in concomitance with coronary artery bypass grafting (CABG) Sixty-one patients (Group I) underwent cardiac surgery with cardioplegic arrest, and 30 patients (Group II) underwent beating heart combined surgery. Aortic valve insufficiency was considered a contraindication for the on-pump/beating heart procedure. Mean age in Group I was 64.4 +/- 7 years and in Group II, 65 +/- 6 years (p = 0.69). RESULTS: The in-hospital mortality in Group I was 8 (13%) patients versus 2 (7%) patients in Group II (p > 0.1). The cardiopulmonary bypass (CPB) time was significantly higher in Group I (p < 0.001). In Groups I and II, respectively (p > 0.1), 2.5 +/- 1 and 2.7 +/- 0.8 grafts per patient were employed. Perioperative complications were identified in 37 (60.7%) patients in Group I versus 10 (33%) patients in Group II (p = 0.025). Prolonged inotropic support of greater than 24 hours was needed in 48 (78.7%) patients (Group I) versus 15 (50%) patients (Group II) (p = 0.008). Postoperative IABP and low cardiac output incidence were significantly higher in Group I, p = 0.03 and p = 0.027, respectively. Postoperative bleeding greater than 1000 mL was identified in 24 patients (39.4%) in Group I versus 5 (16.7%) in Group II (p = 0.033). Renal dysfunction incidence was 65.6% (40 patients) in Group I versus 36.7% (11 patients) in Group II (p = 0.013). The echocardiographic examination within six postoperative months revealed a significant improvement of MV regurgitation fraction, LV function, and reduced dimensions in both groups. The postoperative RF was significantly lower in Group II patients 12 +/- 6 (%) versus 16 +/- 5.6 (%) in Group I (p = 0.001). The 1, 2, and 3 years actuarial survival including all deaths was 91.3%, 84.2%, and 70% in Group I and 93.3%, 87.1%, and 75% in Group II (p = ns). NYHA FC improved significantly in all patients from both groups. CONCLUSION: We conclude that patients with impaired LV function and ischemic MVR may undergo combined surgery with acceptable mortality and morbidity. The on/pump beating heart MV repair simultaneous to CABG offers an acceptable postoperative outcome in selected patients.

The "omega-anastomosis": a new revascularization technique for coronary bifurcations.

We report the "omega-anastomosis," a new technique permitting the revascularization of both coronary branches beyond a bifurcation by using a single arterial graft. This technique consists of a longitudinal incision in the main coronary artery, which extends to both coronary branches beyond the bifurcation. The arterial conduit's distal extremity is cut vertically and tailored to produce a "bipetal" shape, which is used to enlarge and create an acceptable roof for both coronary branches beyond the bifurcation.