Long-term Hemodynamic Effects Research Articles

Association of transcatheter left atrial appendage occlusion with acute changes in left atrial pressure: An invasive hemodynamic study

BackgroundThe hemodynamic effects of transcatheter left atrial appendage occlusion (LAAO) remain unclear. ObjectiveWe sought to assess the effect of LAAO on invasive hemodynamics and their correlation with clinical outcomes. MethodsWe recorded mean left atrial pressure (mLAP) before and after device deployment. We assessed the prevalence and predictors of mLAP increase after deployment, the association between significant mLAP increase after deployment and 45-day peridevice leak (PDL), and the association between mLAP increase and heart failure (HF) hospitalization. A significant mLAP increase was defined as one equal to or greater than the mean percentage increase in mLAP after deployment (≥28%). ResultsWe included 302 patients (36.4% female; mean age, 75.8 ± 9.5 years). After deployment, mLAP increased in 48% of patients, 38% of whom experienced significant mLAP increase. Independent predictors of mLAP increase were baseline mLAP ≤14 mm Hg, nonparoxysmal atrial fibrillation, and age per 5 years (odds ratios: 3.66 [95% CI, 2.21–6.05], 1.81 [95% CI, 1.08–3.02], and 0.85 [95% CI, 0.73–0.99], respectively). Significant mLAP increase was an independent predictor of 45-day PDL (odds ratio, 2.55; 95% CI, 1.04–6.26). There was no association between mLAP increase and HF hospitalization. ConclusionAfter deployment, mLAP acutely rises in 48% of patients, although this is not associated with increased HF hospitalizations. PDL is more likely to develop at 45 days in patients with significant increase in mLAP after deployment, although most leaks were small (<5 mm). These findings suggest that mLAP increase after deployment is not associated with major safety concerns. Additional studies are warranted to explore the long-term hemodynamic effects of LAAO.

Left Bundle Branch Area Pacing Contributes to a Greater Acute Blood Pressure Reduction Compared to Right Ventricular Pacing.

Several previous studies have explored the potential arterial blood pressure (BP) changes in patients undergoing right ventricular pacing (RVP), however, the relationship between left bundle branch area pacing (LBBAP) and BP variations remains unknown. This study aimed to examine the acute BP variations following LBBAP and RVP implantation in patients with bradycardia. We conducted a single-center retrospective study including all patients who underwent de-novo dual-chamber pacemaker implantation between January 2019 and June 2021. Patients were divided into two groups, LBBAP and RVP, and propensity score-matching (PSM) was used to balance confounding factors. Three time periods were defined according to the timing of the implant: baseline (within 24 hours before implantation), hyper-acute period (0-24 hours post-implantation), and acute period (24-48 hours post-implantation). BP was measured at least three times per period using an arm pressure cuff and then averaged for analysis, which allowed us to determine the acute impact of pacemaker implantation on BP. From a cohort of 898 patients, 193 LBBAP receivers were matched to 193 RVP receivers. A significant decrease in systolic BP (SBP) after the implantation was observed in the study cohort, from baseline 137.3 9.2 mmHg to the acute period of 127.7 9.4 mmHg (p 0.001). The LBBAP group exhibited a greater SBP reduction than the RVP group ( 11.6 6.2 mmHg vs. 7.6 5.8 mmHg, p 0.001). In further subgroup analysis, LBBAP receivers who had high baseline SBP (p 0.001) and those without using anti-hypertensive drugs (p = 0.045) appeared to have a higher magnitude of SBP reduction. Permanent pacemaker implantation may contribute to an acute decrease in systolic BP, which was more pronounced in LBBAP receivers. Future experimental and clinical investigations are necessary to explore the underlying mechanisms and the long-term hemodynamic effects of LBBAP versus RVP.

Concurrent Optical- and Magnetic-Stimulation-Induced Changes on Wound Healing Parameters, Analyzed by Hyperspectral Imaging: An Exploratory Case Series.

The effects of concurrent optical and magnetic stimulation (COMS) therapy on wound-healing-related parameters, such as tissue oxygenation and water index, were analyzed by hyperspectral imaging: an exploratory case series. Background: Oedema and inadequate perfusion have been identified as key factors in delayed wound healing and have been linked to reduced mitochondrial respiration. Targeting mitochondrial dysfunction is a promising approach in the treatment of therapy refractory wounds. This sub-study aimed to investigate the effects of concurrent optical and magnetic stimulation (COMS) on oedema and perfusion through measuring tissue oxygenation and water index, using hyperspectral imaging. Patients and methods: In a multi-center, prospective, comparative clinical trial, eleven patients with chronic leg and foot ulcers were treated with COMS additively to Standard of Care (SOC). Hyperspectral images were collected during patient visits before and after treatment to assess short- and long-term hemodynamic and immunomodulatory effects through changes in tissue oxygenation and water index. Results: The average time for wound onset in the eleven patients analyzed was 183 days, with 64% of them being considered unresponsive to SOC. At week 12, the rate of near-complete and complete wound closure was 64% and 45%, respectively. COMS therapy with SOC resulted in an increased short-term tissue oxygenation over the 8-week treatment phase, with oxygen levels decreasing in-between patient visits. The study further found a decrease in tissue water content after the therapy, with a general accumulation of water levels in-between patient visits. This study's long-term analysis was hindered by the lack of absolute values in hyperspectral imaging and the dynamic nature of patient parameters during visits, resulting in high interpatient and intervisit variability. Conclusions: This study showed that COMS therapy as an adjunct to SOC had a positive short-term effect on inflammation and tissue oxygenation in chronic wounds of various etiologies. These results further supported the body of evidence for safety and effectiveness of COMS therapy as a treatment option, especially for stagnant wounds that tended to stay in the inflammatory phase and required efficient phase transition towards healing.

Haemodynamic effects of riociguat in CTEPH and PAH: a 10-year observational study.

BackgroundLong-term treatment with riociguat has been shown to enhance exercise capacity in patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH). This study sought to evaluate the long-term haemodynamic effects of riociguat in patients with PAH and inoperable CTEPH.MethodsDuring this single-centre long-term observational study, riociguat was administered at a three-times-daily dose of up to 2.5 mg. The primary outcome was pulmonary vascular resistance (PVR). The secondary outcomes included mean pulmonary arterial pressure (PAP), cardiac index, mortality, clinical worsening events, 6-min walk distance (6MWD) and World Health Organization functional class (WHO FC).Results37 patients (CTEPH n=19; PAH n=18) were included. The median follow-up period was 96 months. The survival estimates for all the patients at 1/3/5/8 years were 0.97/0.86/0.72/0.61, without significant differences between patients with CTEPH and PAH. At the final data cut-off, PVR decreased (1232±462 dyn·s·cm–5 versus 835±348 dyn·s·cm–5, p<0.001), cardiac index increased (1.7±0.4 L·min−1·m−2 versus 2.4±0.5 L·min−1·m−2, p<0.001), 6MWD increased by 43.1±59.6 m, and WHO FC improved/stabilised/worsened in 40%/35%/25% of patients versus baseline. Improvement in PAP was not shown. Compared with patients in WHO FC I/II and III/IV at baseline, the 8-year clinical worsening-free survival estimates were 0.51 versus 0.19 (p=0.026).ConclusionsRiociguat improved PVR and cardiac index for up to 8 years, but not PAP. WHO FC may have certain predictive value for the long-term prognosis.

NIV sırasında Uzun Süreli Deksmedetomidin Kullanımının Yaşa Bağlı Hemodinamik Etkileri

Objective: Sedation in the intensive care unit plays a key role in patient management as it helps suppress agitation, increases tolerance to stress, and facilitates medical interventions, such as noninvasive ventilation (NIV) Our purpose was to determine the long-term hemodynamic effects of dexmedetomidine in elderly patients with acute respiratory failure who require NIV. Methods: We recorded the data concerning age, comorbidities, doses of dexmedetomidine, hemodynamic parameters, use of vasopressors and length of ICU stay, from the hospital electronic medical recor system Due to the possibility of causing hemodynamic instability in ICU, patients with reduced ventricular contractility, hypothermia, septic shock, endocrine pathologies and neurosurgery cases, were excluded from the study. Results: The patients were evaluated in four age groups: Group I: 18-39 years; Group II, 40-64 years; Group III, 65-80 years, and Group IV, aged &gt;80 years The patients in group IV were found to be at a higher risk for a decrease in MAP following onset of dexmedetomidine treatment (p=0.005*). Notably, most of the vasoactive agents were used in patients over 85 years old (54.2%, p=0.005). With increasing age hypotension and vasopressor needs were found to exhibit a corresponding augmentation. Conclusion: Dexmedetomidine meets requirements for sedation during NIV in the ICU. Even without loading dose the drug can induce hemodynamic instability, therefore close monitoring is necessary. In elderly, dexmedetomidine should be started at the lowest possible dose and slowly titrated according to the patient’s response.

Acute hemodynamic effects of iatrogenic inter-atrial shunts after percutaneous edge-to-edge mitral valve repair

Abstract Background Implantable interatrial shunt devices improve pulmonary vascular function in patients with heart failure by transferring richly oxygenated blood to the right heart. Whether iatrogenic atrial septum defects (iASDs) after percutaneous edge-to-edge mitral valve repair (pMVR) are also associated with beneficial hemodynamic effects has not been investigated. Methods We consecutively enrolled patients with relevant functional (FMR) and degenerative mitral regurgitation (DMR) scheduled for pMVR. Invasive hemodynamic assessments were performed prior to and immediately after the procedure. Results 97 consecutive patients (75.4±9.1 years; 58% female) were prospectively included, 65 (66%) presented with relevant FMR. At baseline when compared to the DMR group, FMR was associated with worse left ventricular (LV) function (LV ejection fraction: 39 vs. 49%; p=0.001), higher NT-proBNP levels (7404 vs. 5214 pg/mL; p=0.023), worse renal function (serum creatinine: 1.7 vs. 1.3 mg/dL; p=0.019), and higher usage of spironolactone (68 vs. 42%; p=0.018) and sacubitril/valsartan (33 vs. 0%; p&amp;lt;0.001). Following pMVR, cardiac output (CO) and systemic blood flow (Qs) increased significantly (CO: 4.6 to 5.5 L/min; p&amp;lt;0.001; Qs: 4.9 to 5.8 L/min; p=0.002), with more pronounced changes in the FMR subgroup (ΔCO: 1.0 vs. 0.6 L/min; Figure 1A; ΔQs: 1.2 vs. 0.1 L/min), when compared to DMR. Pulmonary blood flow (Qp) increased by 26% (4.3 to 5.4 L/min; p=0.008), accompanied by a raise in pulmonary artery (PA) oxygen (O2) saturation from 73 to 77% (p&amp;lt;0.001). Arterial O2 saturation levels remained unchanged (98.3 to 98.7%; p=0.165), confirming no significant changes in systemic oxygenation. These changes were associated with a slight decline in pulmonary vascular resistance (PVR: 250 to 225 dynes*sec/cm5; p=0.369, Figure 1B), and a tendency towards improvement of pulmonary compliance (PAC: 3.6 to 4.0 mL/mmHg; p=0.414). Conclusions Invasively measured CO, Qs, Qp, and mixed-venous PA O2 saturation increased immediately after pMVR, alongside with potentially beneficial effects on pulmonary vasculature with marked improvements in PVR and PAC. These changes were more pronounced in the FMR subgroup. Further studies are required to assess long-term hemodynamic effects and underlying mechanisms of persistent iASDs on pulmonary vascular function. Figure 1. Invasive hemodynamics Funding Acknowledgement Type of funding source: None

Orthostatic and Exercise Effects in Children Years After Kawasaki Disease.

The long-term orthostatic and/or exercise hemodynamic effects in children years after Kawasaki disease (KD) were studied using clinical data from the treadmill exercise test (TMET). Heart rate (HR) and blood pressures (BPs) recorded in TMET were compared between two age, gender, and body scale-matched groups of patients with and without a history of KD. The KD group included 60 patients (9.8 ± 2.7years old) 6.6 ± 2.6years after KD without coronary arterial aneurysm. The non-KD group included 60 children (10.2 ± 2.7years old) with other diagnoses. The exercise tolerance in TMET was not statistically different between the two groups. The KD group had a faster HR on standing than the non-KD group by 8.6% (101.5 ± 12.2 vs. 93.5 ± 15.9bpm, respectively; P < 0.01), suggesting weaker and/or retarded orthostatic vasoconstriction. The pulse pressure was largely augmented above the 4th stage beyond 160mmHg in 10.6 versus 0% (5 vs. 0) of the KD and non-KD groups (P < 0.05), respectively, while HR and BPs were not significantly different through exercise stages between the two groups. The KD group also showed a faster HR recovery five minutes after exercise than the non-KD group, by 5.7% (108.0 ± 11.6 vs. 102.2 ± 14.2bpm, respectively; P < 0.05). Our results might indicate long-term subclinical impacts on the vascular tonus of children years after the disease that have not been recognized in previous studies.

Long-Term Hemodynamic Effects After Carotid Artery Revascularization.

The baroreceptor at the carotid body plays an important role in hemodynamic autoregulation. Manipulation of the baroreceptor during carotid endarterectomy (CEA) or radial force from carotid artery angioplasty and/or stenting (CAS) may cause both intraoperative and postoperative hemodynamic instability. The purpose of this study is to evaluate the long-term effects of CEA and CAS on blood pressure (BP), heart rate (HR), and subsequent changes on antihypertensive medications. A retrospective chart review was performed to identify patients who underwent CEA or CAS between 2009 and 2015 at a single tertiary care institution. Baseline demographics and comorbidities were recorded. Operative details of the carotid artery endarterectomy and the use of balloon angioplasty during the CAS were analyzed. Hemodynamic parameters such as BP, HR, and antihypertensive medication requirement were evaluated at 3, 6, 12, 24, and 36 months. A total of 289 patients were identified. The average age was 70.6 years old, and males constituted 64.0%. All patients had moderate (>50%) to severe (>70%) carotid stenosis. Of those, 111 (40.5%) patients were symptomatic. Systolic BP (mm Hg) of CAS and CEA were similar over the entire follow-up period. Heart rate (beats/min) remained stable postoperatively. A reduced number of antihypertensive medications was observed in the CAS cohort during the first postoperative year when compared to the preoperative baseline: 2.03 at preop, 1.77 ( P < .01) at 3 months, 1.78 ( P = .02) at 6 months, 1.77 ( P = .02) at 12 months, 1.86 ( P = .09) at 24 months, and 2.03 ( P = =.50) at 36 months. Logistic regression analysis identified that CAS (odds ratio [OR]: 2.52, confidence interval [CI]: 1.09-5.83) and multiple (>2) antihypertensive medication use at baseline (OR: 5.89, CI: 2.62-13.26) were predictors for a reduction in the number of antihypertensive medications following carotid revascularization. Surgical intervention for carotid stenosis poses a risk of postoperative hemodynamic dysregulation. Although postoperative BP and HR remained relatively stable after both CAS and CEA, the number of postoperative antihypertensive medications was reduced in the CAS cohort for the first postoperative year when compared to baseline. Patients with multiple antihypertensive agents undergoing CAS should have close postoperative BP monitoring and should be monitored for a possible reduction in their antihypertensive medication regimen.

Acute and Long-Term Hemodynamic Effects of MitraClip Implantation on a Preexisting Secondary Right Heart Failure.

Positive results of MitraClip in terms of improvement in clinical and left ventricular parameters have been described in detail. However, long-term effects on secondary pulmonary hypertension were not investigated in a larger patient cohort to date. 70 patients with severe mitral regurgitation, additional pulmonary hypertension, and right heart failure as a result of left heart disease were treated in the heart centers Hamburg and Göttingen. Immediately after successful MitraClip implantation, a reduction of the RVOT diameter from 3.52 cm to 3.44 cm was observed reaching a statistically significant value of 3.39 cm after 12 months. In contrast, there was a significant reduction in the velocity of the tricuspid regurgitation (TR) from 4.17 m/s to 3.11 m/s, the gradient of the TR from 48.5 mmHg to 39.3 mmHg, and the systolic pulmonary artery pressure (PAPsyst) from 58.6 mmHg to 50.0 mmHg. This decline continued in the following months (Vmax TR 3.09 m/s, peak TR 38.6 mmHg, and PAPsyst 47.4 mmHg). The tricuspid annular plane systolic excursion (TAPSE) increased from 16.5 mm to 18.9 mm after 12 months. MitraClip implantation improves pulmonary artery pressure, tricuspid regurgitation, and TAPSE after 12 months. At the same time, there is a decrease in the RVOT diameter without significant changes in other right ventricular and right atrial dimensions.

Long-term hemodynamic and molecular effects persist after discontinued renin–angiotensin system blockade in patients with type 1 diabetes mellitus

Animal studies suggest temporary renin-angiotensin system (RAS) blockade enhances long-term vascular protective effects; however, this is not established in humans. Here we evaluated the long-term effects of prior RAS blockade on hemodynamic function, urinary measures of inflammation, and tissue antioxidant mRNA expression in patients with type 1 diabetes mellitus (T1DM) who participated in the 5-year Renin Angiotensin System Study (RASS). At 4 years after completing the RASS and discontinuing study medication, renal hemodynamic responses to clamped hyperglycemia were significantly greater in 18 patients in the RAS blockade group compared to 9 patients of the placebo-treated group. Individuals who had received RAS blockade also exhibited higher flow-mediated vasodilatation, reduced urinary cytokine excretion in response to hyperglycemia, and increased skin mRNA expression of superoxide dismutase-1 and catalase. Thus, patients with uncomplicated T1DM who received prior RAS blockade for 5 years maintain long-term effects on renal hemodynamic and systemic vascular function, inflammatory pathways in the kidney, and antioxidant enzyme expression in skin 4 years after discontinuation of therapy. Our findings suggest that sustained long-term protective effects of finite RAS inhibition requires further study.

Very late effects of dual chamber pacing therapy for obstructive, hypertrophic cardiomyopathy

Background: The very long-term effects of dual chamber pacing as a primary treatment for hypertrophic obstructive cardiomyopathy (HOCM) are poorly known and controversial. Objective: To examine the intermediate- and long-term clinical and hemodynamic effects of permanent, dual chamber pacing in patients presenting with HOCM. Methods: Between 1991 and 2007, 51 patients (mean age = 59±14 years) presenting with HOCM and New York Heart Association (NYHA) functional class ≥ 2 despite optimal medical therapy, underwent implants of DDD pacemakers with or without defibrillator and were followed for 11.5 years (range 0.4 - 21.8). Results: During follow-up, no patient underwent myectomy or septal alcohol ablation. NYHA functional class and other disease manifestations decreased significantly between 1 and 2 years of follow-up and remained stable thereafter. The left intraventricular (LV) gradient decreased by a mean of 78% between 1 and 2 years, to reach 89% at the end of follow-up, along with the disappearance of systolic anterior motion of the mitral valve. Mean LV ejection fraction decreased from a mean of 64±8% before pacing to 56±9% at the end of follow-up (P=0.05), while LV end-diastolic diameter did not change significantly. The 5- and 10-year actuarial survival rates were 90 and 65%, respectively. Among 22 deaths, 10 were due to cardiovascular and 12 to non-cardiovascular causes; 2 patients underwent cardiac transplantation after 8 and 13 years of DDD pacing, respectively. Conclusions: In this sample of patients suffering from HOCM, DDD pacing alleviated symptoms and improved hemodynamic function over the very long term. The merits of this treatment should be revisited in a controlled trial.

Cerebral hemodynamics and baroreflex sensitivity after carotid artery stenting

The long-term hemodynamic effects of carotid angioplasty and stenting (CAS) are unclear. We performed a longitudinal study to investigate the variations in cerebral hemodynamics in patients undergoing CAS. We performed prospective evaluation of 63 symptomatic male patients (19 patients had transient ischemic attack and 44 had minor stroke; mean age: 77.3 ± 6.3 years [range: 51-86]). The mean blood flow velocities (MBFV) and pulsatility index (PI) of the middle cerebral arteries (MCA) on both sides were evaluated using transcranial color-coded Doppler (TCCD) ultrasonography. Cardiac autonomic activities were evaluated by measuring baroreflex sensitivity (BRS). All parameters were measured at baseline prior to CAS and at 1, 3, 6, and 12 months after CAS. The preoperative MBFV and PI of the ipsilateral MCA were significantly lower than those of the contralateral side. However, after CAS, MBFV in the ipsilateral MCA increased significantly until 2 weeks after stenting, after which the MBFV gradually decreased and remained stable for 1 year after CAS. Further, we observed a nonsignificant increase in MBFV in the contralateral MCA after CAS. In contrast to the MBFV, the BRS values decreased significantly 1 month after stenting and returned to baseline levels 6 months after CAS. Patients with CAS showed improved global cerebral hemodynamic status. However, the BRS did not normalize initially, and baseline value was achieved at 6 months after stenting.

Short- and Long-Term Hemodynamic and Clinical Effects of Carotid Artery Stenting

Stenosis of the carotid artery may cause reduced hemodynamic and neural function that may be ameliorated with CAS. The goal of this study was to evaluate short- and long-term hemodynamic and clinical effects after CAS. Hemodynamic parameters were acquired by PCT within 1 week before CAS and at 1 week and 1 year (10-13 months) after CAS. In ACA territory, MCA territory, PCA territory, basal ganglia, anterior and posterior CWS and IWS, the rCBF, rCBV, and rMTT were determined in 20 patients with unilateral carotid artery stenosis who underwent CAS. MR and noncontrast CT were performed within 1 week before CAS. Noncontrast CT and carotid arteriography were performed immediately after CAS. Carotid arteriography was performed 1 year after CAS. MRS was performed in 3 measurements. The variance analysis was performed to determine whether there were significant differences among the 3 measurements. No significant differences were found among rCBV in any territory (P > .05). In the non-PCA territories, rMTT decreased and rCBF increased at 1 week after CAS (P < .01), but there was no significant difference between 1-week and 1-year effects (P > .05). For MR spectroscopy, no significant differences were found between 1 week after CAS and pretreatment (P > .05); the 1-year scores improved significantly (P < .01). The long-term hemodynamic and clinical results after treatment validated that CAS is a durable procedure. The 1-week hemodynamic effects can predict long-term effects.

Portal hemodynamics and clinical outcomes of patients with gastric varices after balloon‐occluded retrograde transvenous obliteration

Long-term hemodynamic effects and clinical outcomes after balloon-occluded retrograde transvenous obliteration (B-RTO) remain unclear. The purpose of this study was to evaluate long-term clinical results and effects on portal hemodynamics after B-RTO for the treatment of gastric varices with spontaneous gastrorenal shunt. A total of 21 patients with cirrhosis and gastric varices treated by B-RTO were evaluated. The cumulative survival rate was calculated, portal blood flow was measured by Doppler ultrasonography, and liver function was estimated on the basis of Child-Pugh classification before and 1 year after B-RTO. Gastric varices disappeared or decreased markedly in size in all patients. Overall cumulative survival rates at 1, 3 and 5 years were 90.48, 71.11 and 53.71%, respectively. Portal blood flow increased significantly from 681.9 +/- 294.9 to 837.0 +/- 279.1 ml/min (P = 0.0125) after B-RTO. Child-Pugh score was not significantly changed (P = 0.755) after obliteration, but serum albumin was elevated significantly from 3.49 +/- 0.49 to 3.75 +/- 0.53 g/dl (P = 0.0459). The ascites score was significantly increased (P = 0.0455) after B-RTO, but all cases of ascites could be controlled with medication. Balloon-occluded retrograde transvenous obliteration is a safe and effective treatment for gastric varices with gastrorenal shunt. Portal blood flow and serum albumin parameters are increased, and liver function is unchanged after B-RTO.

Assessment of haemodynamic effects of surgical correction for severe functional tricuspid regurgitation: cardiac magnetic resonance imaging study

There has been growing attention for the development of functional tricuspid regurgitation (TR) long after left-sided valve surgery. We attempted to determine the long-term haemodynamic effects of corrective surgery for severe functional TR in patients who had prior left-sided valve surgery using cardiac magnetic resonance imaging (CMR). Thirty-one patients with severe functional TR (TR fraction of 46.0+/-16.2% by CMR) were analysed. CMR was performed within 1 month before and at a median 27.0 months after surgery. Long after TR surgery, 28 of the 31 patients had no or mild residual TR, two had mild-to-moderate TR, and one showed moderate TR. Remarkable reductions in the right ventricular (RV) end-diastolic volume index (RV-EDVI) (177.4+/-59.1 mL/m(2) vs. 118.2+/-31.2 mL/m(2), P<0.001) and end-systolic volume index (RV-ESVI) (88.5+/-30.1 mL/m(2) vs. 67.2+/-31.0 mL/m(2), P=0.002) were observed, whereas RV ejection fraction (RV-EF) showed no change (49.7+/-8.3% vs. 44.9+/-12.5%, P=0.09). Pre-operative RV-EDVI (R=-0.86, P<0.001) and RV-ESVI (R=-0.55, P=0.001) were significantly associated with their respective changes after corrective surgery. Post-surgery, a normal RV-EF was achieved in 14 patients (42.5%). Pre-operative RV-EDVI of 164 mL/m(2) effectively discriminated patients with normal RV-EF from those without post-surgery, with a sensitivity of 77% and a specificity of 72% (P=0.01). A significant rise in the left ventricular (LV) EDVI and cardiac index (CI) was found after surgery (from 92.9+/-24.4 to 123.2+/-31.6 mL/m(2) for LV-EDVI, P<0.001; from 3.8+/-1.3 to 4.2+/-0.8 L/min/m(2) for CI, P=0.03). Functional capacity as assessed by NYHA class showed a significant improvement from 2.7+/-0.6 before surgery to 2.0+/-0.6 long after surgery (P<0.001). Successful TR surgery can remarkably reduce RV volumes and preserve RV systolic function. In addition, successful TR surgery led to a significant rise in LV preload and CI, which may significantly contribute to a significant amelioration in the functional capacity of the patients. It seems that RV volume measurement by CMR is helpful for determining optimal timing for TR surgery.

Right Ventricular Outflow Tract Septal Pacing: Long‐Term Follow‐Up of Ventricular Lead Performance

The detrimental effects of right ventricular apical pacing on left ventricular function has driven interest in selective site pacing, predominantly on the right ventricular outflow tract (RVOT) septum. There is currently no information on long-term ventricular lead electrical performance from this site. A total of 100 patients with ventricular lead placement on the RVOT septum undergoing pacemaker implantation for bradycardia indications were analyzed retrospectively. Lead positioning was confirmed with the use of fluoroscopy. Long-term (1 year) follow-up was obtained in 92 patients. Information on stimulation threshold, R-wave sensing, lead impedance, and lead complications were collected. Lead performance at the RVOT septal position was stable in the long term. Ventricular electrical parameters were acceptable with stable long-term stimulation thresholds, sensing, and impedance for all lead types. One-year results demonstrated mean stimulation threshold of 0.71 +/- 0.25 V, mean R wave of 12.4 +/- 6.05 mV, and mean impedance values of 520 +/- 127 Omega. There were no cases of high pacing thresholds or inadequate sensing. This study confirms satisfactory long-term performance with leads placed on the RVOT septum, comparable to traditional pacing sites. It is now time to undertake studies to examine the long-term hemodynamic effects of RVOT septal pacing.

Right Ventricular Outflow Tract Septal Pacing: Long-Term Follow-Up of Ventricular Lead Performance

Background: The detrimental effects of right ventricular apical pacing on left ventricular function has driven interest in selective site pacing, predominantly on the right ventricular outflow tract (RVOT) septum. There is currently no information on long-term ventricular lead electrical performance from this site. Methods: A total of 100 patients with ventricular lead placement on the RVOT septum undergoing pacemaker implantation for bradycardia indications were analyzed retrospectively. Lead positioning was confirmed with the use of fluoroscopy. Long-term (1 year) follow-up was obtained in 92 patients. Information on stimulation threshold, R-wave sensing, lead impedance, and lead complications were collected. Results: Lead performance at the RVOT septal position was stable in the long term. Ventricular electrical parameters were acceptable with stable long-term stimulation thresholds, sensing, and impedance for all lead types. One-year results demonstrated mean stimulation threshold of 0.71 ± 0.25 V, mean R wave of 12.4 ± 6.05 mV, and mean impedance values of 520 ± 127 Ω. There were no cases of high pacing thresholds or inadequate sensing. Conclusions: This study confirms satisfactory long-term performance with leads placed on the RVOT septum, comparable to traditional pacing sites. It is now time to undertake studies to examine the long-term hemodynamic effects of RVOT septal pacing.

Role of Myocardial Contractility and Autonomic Control in the Hypotensive Response to a Limited Access Ethanol Paradigm in SHRs

Previous experimental studies that evaluated the chronic hemodynamic effect of ethanol employed the continuous exposure protocol of ethanol, which does not mimic the pattern of alcohol consumption in humans. This study dealt with the long-term hemodynamic and cardiovascular autonomic effects of ethanol, in a limited-access regimen in telemetered spontaneously hypertensive rats (SHRs). Changes in blood pressure (BP), heart rate (HR), myocardial contractility (dP/dt(max)), and spectral cardiovascular autonomic profiles during the ethanol exposure period (2.5 or 5% w/v, 8 h/d, 8:30 am till 4:30 pm) were followed for 12 weeks. Compared with control pair-fed SHRs, body weight and urine output, osmolality, and potassium levels were decreased in SHRs receiving 5% but not 2.5% ethanol. Blood pressure showed progressive falls during ethanol-feeding periods with a maximum effect observed at week 5. The peak hypotensive effect was maintained thereafter in SHRs receiving 5% ethanol in contrast to steady rises in BP in the 2.5% ethanol group to near-control levels by the conclusion of the study. Heart rate was slightly but significantly increased by ethanol 5% whereas dP/dt(max) showed persistent reductions. Power spectral analysis showed that ethanol attenuated the baroreflex gain of HR as suggested by the reductions in index alpha, the spectral index of spontaneous baroreflex sensitivity (BRS). It is concluded that limited access ethanol drinking in SHRs elicited hypotension that was concentration dependent and mediated, at least partly, through reductions in myocardial contractility. Baroreflex sensitivity attenuation by ethanol appeared to have limited the tachycardic response to ethanol and perhaps its capacity to offset the evoked hypotension.

Combination Therapy With Oral Sildenafil and Beraprost for Pulmonary Arterial Hypertension Associated With CREST Syndrome

Pulmonary arterial hypertension (PAH) is commonly associated with CREST (Calcinosis, Raynaud phenomenon, Esophageal motility disorders, Sclerodactyly, and Telangiectasia) syndrome. Sildenafil, an oral phosphodiesterase type-5 inhibitor, may offer benefits in the pharmacological management of PAH. However, little is known about the long-term hemodynamic effects of sildenafil, and the potential role of sildenafil in long-term combination with beraprost, an oral prostacyclin analogue, remains unclear. We therefore examined the hemodynamic effect of oral sildenafil alone and when coadministered with beraprost in a patient with PAH associated with CREST syndrome. Traces of the acute hemodynamic effects of beraprost (20 microg) disappeared after 2 hours. In contrast, the acute hemodynamic effects of sildenafil (50 mg) produced a greater reduction in PAP (31%) and PVR (40%), and these effects also disappeared after 5 hours. After 1 month of combination therapy of sildenafil (25 mg) twice daily and beraprost (20 microg) 3 times daily, the fall in pulmonary artery pressure and pulmonary vascular resistance was sustained (31% in both). Furthermore, the patient had significantly improved her 3-minute walk test and NYHA function class without significant adverse effects at the reported doses. The findings indicate that oral sildenafil is a potent pulmonary vasodilator that appears to act synergistically with oral beraprost to cause sustained pulmonary vasodilatation in a patient with PAH associated with CREST syndrome.

P4-90: Effects of CCM (cardiac contractility modulation) signal delivery on left ventricular contractility

Non-excitatory cardiac stimulation during the refractory period is a novel modality for treating chronic heart failure. Stimuli with an amplitude of up to 7.5 V and a duration of up to 24 ms are delivered during the absolute refractory period. Experimental studies show that CCM stimulation (CCMS) leads to elevated intracellular Ca++ levels and is associated with increased contractility (C) as determined by the velocity of ventricular pressure rise (dp/dt). The FIX-CHF-3 study has proven the safety and acute effectiveness of this therapy. Long-term hemodynamic effects of CCMS are investigated in the European FIX-CHF-4 study.