Changes In Left Atrial Pressure Research Articles

B-57 | Change in Left Atrial Pressure on 12-month Heart Failure Outcomes After MitraClip

B-57 | Change in Left Atrial Pressure on 12-month Heart Failure Outcomes After MitraClip

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.

TCT-65 Association of Transcatheter Left Atrial Appendage Occlusion With Acute Changes in Left Atrial Pressure: An Invasive Hemodynamic Study

TCT-65 Association of Transcatheter Left Atrial Appendage Occlusion With Acute Changes in Left Atrial Pressure: An Invasive Hemodynamic Study

Abstract 13614: Why the Pulmonary Veins: Linking Atrial 4D Flow MRI Derived Biomechanics and Pulmonary Vein Electrical Remodeling

Introduction: Pulmonary veins (PV) often trigger atrial fibrillation (AF). However, the underlying mechanism is not completely understood and predicting who benefits from PV isolation (PVI) is imprecise. We propose that arrhythmogenic PV remodeling may be related to myocardial mechanical function. Flow-encoded cardiac magnetic resonance imaging (4D Flow MRI) based computational modeling enables assessment of left atrial (LA) hemodynamics and biomechanics. In this pilot study, 4D Flow MRI derived parameters were compared to invasive electroanatomic mapping (EAM) and hemodynamics to explore potential non-invasive evaluation of PV remodeling and arrhythmogenicity. Methods: Patients (5 female, 4 male, age 64±6.7 years) with paroxysmal or early persistent AF scheduled for PVI were enrolled. All patients underwent 4D Flow MRI prior to ablation (in sinus rhythm) and intraprocedural EAM (Carto) with atrial pacing under baseline conditions and after increasing LA pressure with a fluid bolus. Non-invasive measures included peak and average velocity (m/s) and net flow (ml/cycle) in each vein (n=36) and averaged for each patient. Apparent conduction velocities in the proximal, mid and distal portions of each vein were calculated under baseline and stretch conditions from EAM. Change in LA pressure per volume bolus, a measure of atrial stiffness, was compared to non-invasive parameters. Results: In patients with LA stiffness greater than median, peak velocities (0.77±0.12 vs. 0.62±0.24 m/s, p=0.26) and net flows were higher (17±2.0 vs. 14.0±2.4 ml/cycle, p=0.06). Patients with paroxysms of spontaneous arrhythmias during mapping had higher LA stiffness (11.5±5.7 vs. 7.6±5.3 mmHg/L, p=0.30). There was a significant correlation between non-invasive average velocity and apparent conduction velocity in the proximal portion of the vein (R=-0.36, p=0.03) and the suggestion of a correlation between increasing peak flow velocity and decreased apparent conduction velocity under stretch conditions compared to baseline (R=-0.24, p=0.16). Conclusions: Our findings may indicate a link between atrial hemodynamics, electrical remodeling and PV arrhythmogenicity. Additional studies are warranted to confirm and better define these findings.

REFERENCE RANGES FOR DOPPLER-ASSESSED FETAL PULMONARY VENOUS BLOOD FLOW VELOCITIES AND PULSATILITY INDICES IN NORMAL GROWTH FETUSES

Background: The aim of this study was to establish reference range with gestation for Doppler parameters in the fetal pulmonary venous blood of normal fetal growth, and indices reflecting left atrial pressure changes. Materials and Methods: Cross-sectional data were collected from 168 normal fetal growth between 28 and 40 weeks of gestation. Investigations of fetal pulmonary veins was performed by Doppler echocardiography to measure parameters: peak systolic velocity (S), peak diastolic velocity (D), end-diastolic velocity (A), and to calculate : peak velocity index for veins (PVIV), pulsatility index for viens (PIV). Regression analysis was used to detemine reference ranges with gestation. Results: Mean maternal age of study population was 29.79 ± 5.47 years old, and mean gestational age was 35.55 ± 2.73 weeks, average birth weight of fetus was 2547 ± 647 gr. A significant increase was observed in S, D, A with advancing gestation. Meanwhile, PVIV and PIV was decreasing significantly by advancing the gestational age. Conclusion: A reference range with gestation for Doppler parameters of fetal pulmonary venous blood of normal fetal growth has been established In the case of a normally growing fetus with a gestational age of 28 to 40 weeks, fetal pulmonary venous Doppler parameters are strongly correlated with gestational age. The flow velocity of the S, D, and A waves increases with gestational age. Peak velocity index (PVIV) and pulse index (PI) decrease with gestational age.

30-day patient reported outcomes can be predicted by change in left atrial pressure and not change in transmitral gradient following MitraClip.

Change in left atrial pressure (LAP) has been shown to be associated with symptom improvement post-MitraClip; however, the association between acute procedural changes in transmitral diastolic mean gradient (MG) compared to LAP and symptom improvement is not well established. 164 consecutive patients undergoing MitraClip at Mayo Clinic between June 2014 and May 2018 were included. Preclip and postclip MG and LAP were recorded. Baseline demographics, clinical, and echocardiographic outcomes, including 30-day New York Heart Association (NYHA) functional status were obtained from patient charts. Median age was 81.5 years (IQR: 76.3, 87), 34% were female and 94.5% had NYHA class III and IV functional status at baseline. At baseline, median MG was 4 mmHg (IQR: 3, 5) and LAP was 19 mmHg (IQR: 16, 23.5). Following MitraClip deployment, the median MG was 4 mmHg (IQR: 3, 6) and the median LAP was 17 mmHg (IQR: 14, 21), 69.5% of patients had less than moderate MR. There was no statistically significant association between change in MG and NYHA functional class at 30 days (OR=0.95, 95% CI: 0.76-1.20). However, a reduction in LAP following MitraClip deployment was significantly associated with improvement in NYHA functional status at 30 days following adjustments for age and sex (aOR 3.36, 95% CI: 1.34-8.65). There was no significant correlation between change in mean LAP and change in MG (p=.98). Unlike change in left atrial pressure, change in MG post-MitraClip was not associated with patient reported outcomes at 30 days and did not correlate with change in left atrial pressure. Long-term follow up is needed to evaluate the impact of LA pressure on symptoms.

The hemodynamic effect of different left ventricular unloading techniques during veno-arterial extracorporeal life support: a systematic review and meta-analysis.

Pulmonary edema and left ventricular thrombosis may arise during veno-arterial extracorporeal life support due to an increase in cardiac load. This mechanical stress can be reduced through different left ventricular unloading techniques. We set out to quantitatively summarize the hemodynamic effects of available methods in patients treated with veno-arterial extracorporeal life support. Literature was systematically searched for studies reporting left ventricular unloading during veno-arterial extracorporeal life support as reflected by changes in left atrial pressure, pulmonary capillary wedge pressure, diastolic pulmonary artery pressure, or left ventricular end-diastolic pressure. For studies including ⩾10 patients per group, changes in these parameters were pooled using (1) standardized mean differences and (2) ratio of means. Assessment of potential bias was performed for all studies. Eight studies met the inclusion criteria. Reported techniques included use of intra-aortic balloon pump (n = 1), micro-axial blood pump (Impella®, n = 2), left ventricular venting (n = 1), and atrial septostomy (n = 4). Overall, left ventricular unloading was associated with a statistically significant reduction in preload parameters (standardized mean differences = -1.05 (95% confidence interval = -1.24 to -0.86) and ratio of means = 0.60 (0.47 to 0.76)). Effect sizes were strongest for micro-axial blood pump and atrial septostomy (standardized mean differences = -1.11 (-1.55 to -0.68) and -1.22 (-1.47 to -0.96), and ratio of means = 0.58 (0.39 to 0.86) and 0.54 (0.36 to 0.83), respectively). Left ventricular unloading was associated with a significant reduction in left ventricular preload parameters in the setting of veno-arterial extracorporeal life support. This effect may be most pronounced for micro-axial blood pump and atrial septostomy.

Hemodynamics of the diastolic pressure gradients in acute heart failure: implications for the diagnosis of pre-capillary pulmonary hypertension in left heart disease.

The diastolic pressure gradient (DPG) has been proposed as the metric of choice for the diagnosis of pulmonary vascular changes in left heart disease. We tested the hypothesis that this metric is less sensitive to changes in left atrial pressure and stroke volume (SV) than the transpulmonary gradient (TPG). We studied the effect of dynamic changes in pulmonary capillary wedge pressure (PCWP), SV, and pulmonary artery capacitance (PAC) on DPG and TPG in 242 patients with acute heart failure undergoing decongestive therapy with continuous hemodynamic monitoring. There was a close impact of PCWP reduction on TPG and DPG, with a 0.13 mmHg (95% confidence interval [CI] 0.07–0.19, P < 0.0001) and 0.21 mmHg (95% CI 0.16–0.25, P < 0.0001) increase for every 1 mmHg decrease in PCWP, respectively. Changes in SV had a negligible effect on TPG and DPG (0.19 and 0.13 mmHg increase, respectively, for every 10-mL increase in SV). Heart rate was positively associated with DPG (0.41-mmHg increase per 10 BPM [95% CI 0.22–0.60, P < 0.0001]). The resistance-compliance product was positively associated with both TPG and DPG (2.65 mmHg [95% CI 2.47–2.83] and 1.94 mmHg [95% CI 1.80–2.08] for each 0.1-s increase, respectively). In conclusion, DPG is not less sensitive to changes in left atrial pressure and SV compared with TPG. Although DPG was not affected by changes in PAC, the concomitant increase in the resistance-compliance product increases DPG.

Pulmonary Venous Waveforms Predict Rehospitalization and Mortality After Percutaneous Mitral Valve Repair

ObjectivesIn this study, the authors hypothesized that intraprocedural improvement of pulmonary venous (PV) waveforms are predictive of improved outcomes. In this report, they analyzed intraprocedural invasive and echocardiographic changes with respect to rehospitalization and mortality. BackgroundThe effects of hemodynamic changes during percutaneous mitral valve repair (PMVR) with MitraClip (Abbott Vascular, Santa Clara, California) are incompletely characterized. MethodsThe authors retrospectively reviewed records and intraprocedural transesophageal echocardiograms of 115 consecutive patients (age 76 ± 12 years) who underwent PMVR for mitral regurgitation (MR) from May 2013 to January 2017 at Emory University Hospital. They assessed intraprocedural PV waveforms for improvement in morphology, measured change in MR grade by semiquantitative methods, evaluated invasive changes in left atrial pressure (LAP) and V-wave, and compared with 30-day and 1-year rehospitalization and all-cause mortality. ResultsNinety-three cases (80%) had PV waveforms before and after clip placement sufficient for analysis, of which 67 (73%) demonstrated intraprocedural improvement in PV morphology and 25 (27%) did not. At 24 months, 57 (85%) of those with PV improvement were living, compared with only 10 (40%) of those without improvement. Proportional hazards models demonstrated a significant survival advantage in those with PV improvement (hazard ratio [HR]: 0.28, 95% confidence interval [CI]: 0.08 to 0.93, p = 0.038). By multivariable analysis, PV improvement predicted reduced 1-year cardiac rehospitalization (odds ratio [OR]: 0.18, p = 0.044). Intraprocedural assessment of MR grade and invasive hemodynamics did not consistently predict mortality and rehospitalization. ConclusionsPV waveforms are important markers of procedural success after PMVR. Our data show intraprocedural PV waveforms may predict rehospitalization and mortality after PMVR. A larger, multicenter cohort will be important to clarify this relationship.

Effect of saline administration on left atrial pressure during transcatheter mitral valve repair.

To measure the intraprocedural change in left atrial pressure (LAP) with saline administration during transcatheter mitral valve repair (TMVR). TMVR with MitraClip offers an alternative to surgery in select patients. During this procedure, large volumes of fluid are routinely administered with anesthesia and to facilitate transcatheter valve repair. LAP, a measure used to guide repair, may thereby change as a result of volume expansion, suggesting a need for continuous intracardiac pressure monitoring. Consecutive patients with severe mitral regurgitation underwent TMVR with MitraClip and continuous LAP monitoring through a dedicated sampling catheter. Specific LAP values were acquired immediately after transseptal access; before first clip deployment; and after deployment of the last clip. 151 patients (age 80 ± 8 years, 64% male) underwent TMVR with MitraClip and continuous LAP monitoring. Mean LAP and v-wave pressure increased significantly from baseline to pre-MitraClip deployment (P < 0.0001) and decreased significantly from deployment to procedure end (P < 0.0001). Linear regression of v-wave pressure change (from procedure start to clip deployment) relative to volume administration yielded a significantly nonzero slope (0.28 mmHg/min, P < 0.0001, r = 0.30). Fluid administration during TMVR leads to time-dependent increases in LAP. Such intraprocedural change underscores the need for targeted, if not continuous, LAP measurement during TMVR to optimize MitraClip placement and mitral regurgitation reduction.

Changes in Left Atrial Function After Transcutaneous Mitral Valve Repair

Left atrial (LA) reverse remodeling occurs after transcatheter mitral valve repair, but additional data are needed about changes in LA function. Changes in LA stiffness in patients undergoing MitraClip implantation were evaluated. Baseline, procedural, and 30-day follow-up clinical and imaging data of patients undergoing MitraClip were reviewed. LA operating chamber stiffness was calculated as the ratio of systolic change in LA pressure to LA systolic strain and to stroke volume. Matched preprocedure and postprocedure LA strain analyses were performed in 35 patients, 21 with primary and 14 with functional mitral regurgitation (MR). Procedural success occurred in 34 of 35 cases with significant improvement of all invasive hemodynamic parameters. LA operating chamber stiffness decreased significantly in the overall population (p <0.001). At follow-up, sustained improvement in MR severity occurred, together with left ventricular (LV) and LA reverse remodeling. After MitraClip deployment, LA operating chamber stiffness showed a significant correlation with follow-up pulmonary artery systolic pressure, LV end systolic volume, and LV EF, irrespective of MR etiology (p <0.05). A significant inverse correlation was seen between change in LA operating chamber stiffness and improvement in 6-min walking distance. In conclusion, LA operating chamber stiffness decreases after MitraClip deployment, irrespective of MR etiology. It is related to pulmonary artery systolic pressure and functional status.

Left atrial compliance: an overlooked predictor of clinical outcome in patients with mitral stenosis or atrial fibrillation undergoing invasive management.

In the assessment of cardiovascular disease, the clinical significance of left atrial (LA) pressure-volume relations has largely been overlooked in contrast to left ventricular (LV) compliance. However, LA compliance has recently gained more attention. Net atrioventricular compliance (Cn), a joint measure of LA and LV compliance, can be calculated non-invasively by a previously validated method using parameters from standard echocardiography. Compliance measurement may be of relevance in selected clinical settings. First, subjects with low Cn are more likely to have their mitral valve area overestimated by the traditional mitral pressure half-time method. Consequently, low Cn in mitral stenosis, usually resulting from reduced LA compliance, can be mistaken for mild mitral stenosis. Second, low Cn independently predicted pulmonary hypertension and disease progression in medically treated mitral stenosis, and late cardiovascular complications after successful percutaneous mitral valvuloplasty. Decreased LA compliance also accounts for stiff LA syndrome, a rare complication of radiofrequency catheter ablation for atrial fibrillation, manifesting as otherwise unexplained heart failure with elevated LA pressure and pulmonary hypertension. Finally, depressed pre-ablation LA stiffness index, i.e. the ratio of the change in LA pressure to the corresponding change in LA volume during passive LA filling, was an independent predictor of arrhythmia recurrence. Thus, LA stiffening translates into adverse clinical outcomes in patients with mitral stenosis or atrial fibrillation undergoing interventional procedures. Whether reduced LA compliance after LA appendage occlusion can result in the LA stiff syndrome, has not been reported so far.

Acute Changes in Left Atrial Pressure After MitraClip Are Associated With Improvement in 6-Minute Walk Distance.

Data on the clinical use of left atrial (LA) hemodynamic monitoring during MitraClip procedure are limited. This study evaluated the association between intraprocedural changes in LA pressure after MitraClip and improvement in exercise capacity as documented by 6-minute walk test (6MWT). Study population included 50 patients who underwent MitraClip at the Mayo Clinic (Rochester, MN), between June 2014 and July 2016 and completed both baseline and 30-day follow-up 6MWT. Primary outcome for the current analysis was defined as 6MWT improvement above the median. Mean age of the study population was 79±10 years, and 34 (68%) were men. Baseline preprocedural 6MWT distance was 308 m (interquartile range [IQR], 234-394 m). Acute, intraprocedural change in LA pressure after MitraClip was 3 mm Hg (IQR, 1-6 mm Hg), and change in V wave was 11 mm Hg (IQR, 6-19 mm Hg). Median 6MWT improvement was 25 m (IQR, 19-47 m). Univariate analysis showed that patients with ≤ mild postprocedural mitral regurgitation were 4-fold more likely to experience an improvement in 6MWT (P=0.02). Multivariate model demonstrated that each 5 mm Hg decrease in V wave was associated with 49% increased likelihood for improvement in 6-minute walk (P=0.04). Similar model with V-wave change as a dichotomous variable showed that patients with a V-wave decrease of ≥11 mm Hg were 3.8× more likely to improve their 6MWT (P=0.05). Acute changes in LA pressure after MitraClip procedure are associated with clinical improvement as measured by 6MWT. Continuous LA pressure monitoring may be a useful tool for procedural guidance during transcatheter mitral repair.

Changes in Mitral Annular Ascent with Worsening Echocardiographic Parameters of Left Ventricular Diastolic Function.

Background. While the mitral annular plane systolic excursion (MAPSE) has been suggested as a surrogate measurement of left ventricular ejection fraction, less is known about the relative value of mitral annular ascent (MAa). Methods. Our database was queried for complete transthoracic echocardiograms performed for any clinical indication. Baseline echocardiographic measurements were compared to determine any correlation between MAa and traditional Echo-Doppler echocardiographic measures to characterize left ventricular diastolic dysfunction (LVDD). Results. Patients with normal LV diastolic function were younger (41 ± 13 years) than patients with LVDD (stage 1: 61 ± 13 years; stage 2: 57 ± 14 years; and stage 3: 66 ± 17 years; p = 0.156). LV ejection fraction decreased in patients with stage 2 LVDD (63 ± 17%) and was further reduced in patients with stage 3 LVDD (28 ± 21; p = 0.003). Discussion. While a vigorous MAa excursion was seen in patients with stage 1 LVDD, MAa significantly decreased in stage 2 and stage 3 LVDD patients. Our results highlight the importance of atrioventricular coupling, as MAa motion seems to reflect changes in left atrial pressure. Additional studies are now required to better examine atrioventricular interactions and electromechanical coupling that might improve our assessment of LV diastolic function.

Percutaneous left atrial decompression in patients supported with extracorporeal membrane oxygenation for cardiac disease.

Left atrial decompression using cardiac catheterization techniques has been described at centers with extracorporeal membrane oxygenation programs. Left atrial decompression can decrease cardiogenic edema, minimize ventricular distension, and allow myocardial recovery. We describe Boston Children's Hospital's experience with percutaneous left atrial decompression techniques, acute outcomes, and clinical impact of left atrial decompression in extracorporeal membrane oxygenation patients. Patients supported with extracorporeal membrane oxygenation undergoing percutaneous left atrial decompression were identified and assigned to two groups 1) myocarditis/suspected myocarditis or 2) nonmyocarditis cardiac disease. Three techniques including vent placement, static balloon dilation, and stent implantation were used. Change in left atrial pressure and severity of pulmonary edema on chest radiography pre and post procedure, impact of timing and technique of left atrial decompression on resolution of left atrial hypertension, and extracorporeal membrane oxygenation survival were evaluated. Furthermore, we evaluated the presence of residual atrial septal defect during follow-up. Percutaneous left atrial decompression was performed in 44 of 419 extracorporeal membrane oxygenation cases (10.5%) and was frequently used for myocarditis (22 of 44 patients; 50%). Techniques included 25 vents, 17 static balloon dilations, and two stents. All techniques were equally successful and significantly reduced left atrial pressure and pulmonary edema. Survival to hospital discharge was not associated with extracorporeal membrane oxygenation duration prior to left atrial decompression, change in left atrial pressure, or technique used. Persistent atrial septal defect was noted in five surviving patients (excluding transplant recipients and deceased), two required closure. Left atrial decompression can be performed effectively in children on extracorporeal membrane oxygenation using various percutaneous techniques. Reduction in pulmonary venous congestion is usually evident by chest radiography within 48 hours of intervention. Persistent atrial septal defect may require closure at the time of extracorporeal membrane oxygenation decannulation or during long-term follow-up.

The Effect of Open‐Irrigated Radiofrequency Catheter Ablation of Atrial Fibrillation on Left Atrial Pressure and B‐Type Natriuretic Peptide

Open-irrigated radiofrequency catheter ablation (oiRFA) of atrial fibrillation (AF) imposes a volume load and risk of pulmonary edema. We sought to assess the effect of volume administration during ablation on left atrial (LA) pressure and B-type natriuretic peptide (BNP). LA pressure was measured via transseptal sheath at the beginning and end of 44 LA ablation procedures in 42 patients. BNP plasma levels were measured before and after 10 procedures. A median of 3,255 (interquartile range [IQR], 2,014)-mL saline was administered during the procedure. During LA ablation, the median fluid balance was +1,438 (IQR, 1,109) mL and LA pressure increased by median 3.7 (IQR, 5.9) mm Hg (P < 0.001). LA pressure did not change in the 19 procedures with furosemide administration (median ΔP = -0.3 [IQR, 7.1] mm Hg, P = 0.334). The correlation of LA pressure and fluid balance was weak (rs = 0.383, P = 0.021). BNP decreased in all four procedures starting in AF or atrial tachycardia and then converting to sinus rhythm (P = 0.068), and increased in all six procedures starting and finishing in sinus rhythm (P = 0.028). After ablation, symptomatic volume overload responding to diuresis occurred in three patients. A substantial intravascular volume load during oiRFA can be absorbed with little change in LA pressure, such that LA pressure is not a reliable indicator of the fluid balance. Subsequent redistribution of the volume load imposes a risk after the procedure. Conversion to sinus rhythm may improve ability to acutely accommodate the volume load.

Abstract 19158: MRI Based Non-Invasive Measures Correlates With Invasive Measurements of Left Atrial Diastolic Function in Atrial Fibrillation Patients

Background: Atrial fibrillation (AF) is associated with diminished cardiac functions. This study describes a novel methodology for non-invasive measurement of left atrial (LA) function in patients with AF. Methods: A total of 55 patients (81% male, 55% paroxysmal, 60.4±10.2 years) underwent cardiac MRI prior to AF ablation. Invasive LA pressure was measured during sinus rhythm following trans-septal puncture for AF ablation. LA pressure and volume (MRI derived) loops were prepared for all patients. LA diastolic function was defined as the ratio of the change in LA pressure to the change in LA volume during passive LA filling. Additionally, the ratio of pulmonary vein flow velocities during ventricular systole and diastole were obtained using phase contrast MRI (Figure top panel, S/D ratio). Patients with ventricular diastolic dysfunction (as seen by E/A ratio) were excluded. LA systolic functions were calculated from the active emptying fraction during atrial contraction. Diastolic dysfunction scores greater than the 90th %tile (&gt;1.6mmHg/ml) were considered to signify severe diastolic dysfunction. Results: The mean diastolic dysfunction score was 0.76±0.7 mmHg/ml. The score was higher in patients with persistent versus paroxysmal AF (1.0±0.9 vs. 0.60±0.5,p=0.02). The mean S/D ratio was 1.04±0.6; and was lower in patients with persistent versus paroxysmal AF (0.9±0.5 vs. 1.2±0.7, p=0.04). There was a negative linear association between diastolic dysfunction scores and S/D ratio measures (Figure bottom panel, p &lt;0.001). In a multivariate analysis adjusting for age, LA systolic function and CHADS2 score, the severe diastolic dysfunction was independently associated with lower S/D ratio (p-0.03). Conclusion: The non-invasive MRI derived ratio of pulmonary vein flow velocities during systole and diastole are associated with the MRI/invasive derived diastolic dysfunction score, and appear to be a fair surrogate of LA diastolic function.

Activation and Entrainment Mapping of Hemodynamically Unstable Ventricular Tachycardia Using a Percutaneous Left Ventricular Assist Device

Our goal was to investigate the effects of percutaneous left ventricular assist device (pLVAD) support during catheter ablation of unstable ventricular tachycardia (VT). Mechanical cardiac support during ablation of unstable VT is being increasingly used, but there is little available information on the potential hemodynamic benefits. Twenty-three consecutive procedures in 22 patients (ischemic, n = 11) with structural heart disease and hemodynamically unstable VT were performed with either pLVAD support (n = 10) or no pLVAD support (intra-aortic balloon pump counterpulsation, n = 6; no support, n = 7). Procedural monitoring included vital signs, left atrial pressure, arterial blood pressure, cerebral perfusion/oximetry, VT characteristics, and ablation outcomes. The pLVAD group was maintained in VT significantly longer than the non-pLVAD group (66.7 min vs. 27.5 min; p = 0.03) and required fewer early terminations of sustained VT for hemodynamic instability (1.0 vs. 4.0; p = 0.001). More patients in the pLVAD group had at least 1 VT termination during ablation than non-pLVAD patients (9 of 10 [90%] vs. 5 of 13 [38%]; p = 0.03). There were no differences between groups in duration of cerebral deoxygenation, hypotension or perioperative changes in left atrial pressure, brain natriuretic peptide levels, lactic acid, or renal function. In patients with scar-related VT undergoing catheter ablation, pLVAD support was able to safely maintain end-organ perfusion despite extended periods of hemodynamically unstable VT. Randomized studies are necessary to determine whether this enhanced ability to perform entrainment and activation mapping will translate into a higher rate of clinical success.

Echocardiographic Evaluation of Diastolic Function Can Be Used to Guide Clinical Care

For normal cardiac performance, the left ventricle (LV) must be able to eject an adequate stroke volume at arterial pressure (systolic function) and fill without requiring an elevated left atrial (LA) pressure (diastolic function). These systolic and diastolic functions must be adequate to meet the needs of the body both at rest and during stress. Response by Tschope and Paulus on p 809 Systolic function is conveniently (although not always accurately) measured as the ejection fraction (EF), calculated as stroke volume divided by end-diastolic volume.1 The LV EF is easily interpreted. The lower limit of normal is ≈50%. The lower the EF is, the greater the reduction in systolic function. Diastolic function has been more difficult to evaluate.2 Traditionally, invasive measures of LV diastolic pressure-volume relations and the rate of LV pressure fall during isovolumetric relaxation have been used. However, these methods are not practical for routine clinical use and do not adequately evaluate all aspects of diastolic filling.3 Comprehensive echocardiographic evaluation of the dynamics of LV filling using blood pool and tissue Doppler has now progressed so that it provides clinically important information that can be used to direct patient care. We present data that support the use of echocardiographic evaluation of diastolic function to recognize cardiac dysfunction in patients with heart failure, especially those with preserved EF; to guide the management of patients by identifying those with and without elevated left filling pressures regardless of underlying EF; and to determine prognosis in a wide variety of patient populations. Although the LV end-diastolic pressure-volume relation describes the passive properties of the LV, LV filling is not a passive or slow process.3 In fact, the peak flow rate across the mitral valve is equal to or greater than the peak flow rate across the aortic valve. …

Impact of left atrial appendage exclusion on left atrial function

We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear. Nineteen mongrel dogs (29.7 +/- 5.2 kg) in sinus rhythm were studied. The Doppler signals from the pulmonary venous flow, transmitral flow, and tissue Doppler imaging of mitral annular motion were obtained before and after left atrial appendage exclusion. Dogs were evaluated in the same manner at 7 days (n = 2), 30 days (n = 7), or 90 days (n = 10) after left atrial appendage exclusion. Except for a significant increase in early diastolic transmitral flow velocity after left atrial appendage exclusion (P = .01), no significant differences were found in any parameters related to the transmitral flow and tissue Doppler imaging measurements throughout follow-up. The systolic components of pulmonary venous flow at follow-up revealed a significant reduction relative to baseline (peak systolic velocity P < .0001, systolic velocity-time integral P < .0001), despite the lack of significant changes in left atrial pressure, left ventricular volume, and stroke volume. Left atrial appendage exclusion may affect left atrial reservoir function in the short-term and midterm periods. Further long-term studies with more clinically relevant models are needed.