Cardiac resynchronization therapy acutely improves ventricular-arterial coupling by reducing the arterial load: assessment by pressure-volume loops.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been demonstrated to improve ventricular-arterial coupling by reducing effective arterial elastance (Ea) on long-term follow-up. Detailed invasive studies showing possible acute peripheral effects of CRT are not available. We evaluated the hemodynamic effects of CRT in patients with systolic dysfunction, in order to investigate the impact on ventricular-arterial coupling and, in particular, on Ea immediately after the initiation of pacing. METHODS: We studied 37 heart failure patients undergoing CRT implantation based on conventional criteria. On implantation, left ventricular (LV) pressure and volume data were determined via a conductance catheter. Twelve patients with a standard indication for electrophysiologic study and preserved LV function served as a control group. RESULTS: In comparison with the control group, heart failure patients showed reduced systolic and diastolic function. LV end-systolic elastance (Ees: end-systolic pressure/volume) was impaired (0.79 ± 0.33 mm Hg/mL vs 1.84 ± 0.89 mm Hg/mL, P = 0.012) and Ees/Ea reduced (0.36 ± 0.17 vs 1.19 ± 1.81, P = 0.022). In heart failure patients, CRT immediately improved systolic function, increasing stroke work from 3.9 ± 1.8 L*mm Hg to 6.9 ± 3.3 L*mm Hg (P < 0.001) and Ees to 1.02 ± 0.62 mm Hg/mL (P = 0.001). Ea decreased from 2.59 ± 1.35 mm Hg/mL to 1.68 ± 0.91 mm Hg/mL (P < 0.001), leading to an increase in Ees/Ea to 0.70 ± 0.38 (P < 0.001). CONCLUSION: Our data indicate that switching CRT on induces an immediate reduction in arterial load, conceivably as a consequence of restored autonomic balance.

Training-induced dynamic changes in left atrial reservoir, conduit, and active volumes in professional soccer players.

PURPOSE: Although left atrial (LA) enlargement is a recognized component of athlete's heart, dynamic cavity changes occurring during the training period remain to be elucidated. We aimed to investigate the adaptive changes of LA reservoir, conduit, and active volumes in elite athletes vs. controls and their response to different training loads. METHODS: LA maximum, pre-P, and minimum volumes were assessed in 26 top-level athletes and 23 controls. In athletes, LA volumes were measured at pre-, mid-, end-training, and post-detraining time points using conventional 2D echocardiography. RESULTS: Athletes had larger maximum (27.5 ± 3.2 vs. 20.3 ± 5.8 mL/m(2), p = 0.001), pre-P (11.5 ± 0.9 vs. 9.8 ± 2.2 mL/m(2), p = 0.001), and minimum (6.6 ± 0.9 vs. 5.0 ± 1.2 mL/m(2), p < 0.001) LA indexed volumes, compared with controls. Total and passive emptying volume indices were also larger in athletes compared with controls (18.7 ± 3.1 vs. 15.3 ± 4.9 mL/m(2), p < 0.05 and 13.8 ± 2.9 vs. 10.5 ± 4.6 mL/m(2), p < 0.05, respectively), while active emptying volume was similar (p = 0.74). During training, LA maximum (p < 0.0001), pre-P (p < 0.0001), minimum (p < 0.0001), total (p < 0.005), and passive (p < 0.05) emptying volume indices progressively increased, while active emptying volume (p = 0.10) and E/e' ratio (p = 0.32) remained unchanged. After detraining, LA volume measurements were not different from pre-training ones. End-training left ventricular mass index was the only independent predictor of the respective maximum LA volume (ß = 0.74, p < 0.005). CONCLUSIONS: Top-level athletes exhibit a dynamic morphological and functional LA remodeling, induced by training, with an increase in reservoir and conduit volumes, but stable active volume. LA remodeling is closely associated with left ventricular adaptation to exercise and both completely regress after detraining.

Simplified Selvester Score: a practical electrocardiographic instrument to predict response to CRT.

AIMS: To investigate the LBBB Selvester Scoring System (LBBB-SSc) and the Simplified-SSc prognostic impact in predicting response to CRT, all cause and cardiac mortality, heart failure (HF) hospitalizations and onset of arrhythmias in HF patients undergoing CRT. METHODS: We retrospectively evaluated LBBB-SSc and Simplified-SSc of 172 consecutive HF patients with true-LBBB who underwent CRT. Response to CRT was defined as the improvement of LVEF of at least 10% or as the reduction of LVESV of at least 15% at 6-month follow-up. Logistic regression analysis and Cox proportional hazard analysis were performed to evaluate each endpoint related risk according to LBBB-SSc and Simplified-SSc. RESULTS: The LBBB-SSc and the Simplified-SSc were inversely correlated with response to CRT. Myocardial scar at both scores was independently associated to non-response to CRT. No correlation was observed between LBBB-SSc or Simplified-SSc and other endpoints. CONCLUSIONS: In HF patients with true-LBBB, Simplified-SSc is able to predict response to CRT.

Impact of dexmedetomidine on electrophysiological properties and arrhythmia inducibility in adult patients referred for reentrant supraventricular tachycardia ablation.

BACKGROUND: Drugs used for sedation/analgesia may affect the basic cardiac electrophysiologic properties or even supraventricular tachycardia (SVT) inducibility. Dexmedetomidine (DEX) is a selective alpha-2 adrenergic agonist with sedative and analgesic properties. A comprehensive evaluation on use of DEX for reentrant SVT ablation in adults is lacking. The present study aims to systematically assess the impact of DEX on cardiac electrophysiology and SVT inducibility. METHODS: Hemodynamic, electrocardiographic, and electrophysiological parameters and SVT inducibility were assessed before and after DEX infusion in patients scheduled for ablation of reentrant SVT. RESULTS: The population of this prospective observational study included 55 patients (mean age of 58.7 ± 14 years, 29 males [52.7%]). A decrease in systolic and diastolic blood pressure and in heart rate was observed after DEX infusion (p = 0.001 for all). DEX increased corrected sinus node refractory time, atrial effective refractory period, AH interval, AV Wenckebach cycle length, and AV node effective refractory period without affecting the His-Purkinje conduction or ventricular myocardium refractoriness. No AV blocks or sinus arrests occurred during DEX infusion. Globally, there was no difference in SVT inducibility in basal condition or after DEX infusion (46/55 [83.6%] vs. 43/55 [78.1%] patients; p = 0.55), without a difference in isoprenaline use (p = 1.0). In 4 (7.3%) cases, the SVT was inducible only after DEX infusion. In 34.5% of cases, DEX infusion unmasked the presence of an obstructive sleeping respiratory pattern, represented mainly by snoring. CONCLUSIONS: DEX depresses sinus node function and prolongs atrioventricular refractoriness without significantly affecting the rate of SVT inducibility in patients scheduled for reentrant SVT ablation.

Clinical impact of smoking on atrial fibrillation recurrence after pulmonary vein isolation.

BACKGROUND: The clinical impact of smoking on atrial fibrillation (AF) recurrences after pulmonary vein isolation (PVI) have contradictory results in previous studies, performed on Asian populations. METHODS AND AIM: Smoking habit and other cardiovascular risk-factors were assessed in patients who underwent their first radiofrequency PVI for symptomatic AF. The study aims to assess the clinical impact of smoking on AF recurrences after PVI in a contemporary European cohort of patients. RESULTS: The study included 186 consecutive patients (135 males [72.6%]) with a mean age of 63.4 ± 9.7 years. Current smokers resulted 29 (15.7%). No statistically significant baseline differences were detected between current smokers and non-current smokers. After a follow-up of 418 ± 246 days, AF recurrence was higher in currently smoking patients vs. non-currently smoker patients, the latter intended as a combination between previous smokers and never smokers (34.5% vs. 14% p = 0.01). A previous smoking habit was not associated with increased risk of AF recurrence when compared with patients who never smoked (13.2% vs. 14.6%, p = 0.23), while a current smoking habit impacted on AF recurrence in comparison with previous smokers (p = 0.01) and never smokers (p = 0.04). The increased incidence of AF recurrence in current smokers was consistent also considering only paroxysmal AF (31.4% vs 9.6%, p = 0.012) or persistent AF (50% vs 31.2%, p = 0.03). Smoking (HR =2.96 95% CI 1.32-6.64) and persistent AF (HR =2.64 95% CI 1.22-5.7) resulted independent predictors of AF recurrence. CONCLUSION: Cigarette smoking is associated with an increased risk of AF recurrences after PVI, both in paroxysmal and in persistent AF.

Larger interventricular conduction time enhances mechanical response to resynchronization therapy.

BACKGROUND: Previous studies have reported that the left ventricular (LV) pacing site is a major determinant of the hemodynamic response to cardiac resynchronization therapy (CRT). However, lead positioning in a lateral or posterolateral cardiac vein may not be optimal for every patient. The objective of this study was to assess the relationship between the right ventricular (RV)-to-LV conduction time and the systolic function during CRT on the basis of changes to LV pressure-volume loops. METHODS: Left ventricular pressure and volume data were determined using a conductance catheter during CRT device implantation in 10 patients. Four endocardial LV sites were systematically assessed at four atrioventricular delays. The RV-to-LV conduction time was measured as the time interval between spontaneous peak R waves, recorded through the RV lead and the LV catheter. RESULTS: The optimal pacing site varied among patients. However, the pacing site associated with the maximum RV-to-LV conduction time resulted in a stroke volume improvement comparable to the pacing site identified through individual hemodynamic optimization (41 ± 17 mL vs 44 ± 18 mL, P = 0.266). Moreover, the RV-to-LV conduction time recorded at each endocardial pacing site correlated positively with the increase in stroke volume (r = 0.537; P < 0.001), stroke work (r = 0.642; P < 0.001), and the pressure-derivative maximum (r = 0.646; P < 0.001) obtained with CRT. CONCLUSIONS: An optimal acute response to CRT can be obtained by positioning the LV lead at the site associated with the maximum RV-to-LV conduction time. A significant correlation appears to exist between RV-to-LV conduction time and the improvement in systolic function with CRT.

Effect of bosentan on pulmonary hypertension secondary to systolic heart failure.

OBJECTIVES: The dual endothelin receptor antagonist bosentan improves pulmonary vascular resistance (PVR) in patients with primary pulmonary hypertension (PH). The effects of bosentan on secondary PH due to systolic heart failure (HF) are not well defined. This study evaluates the effect and tolerability of bosentan in patients with PH secondary to HF. METHODS: Seventeen adult HF patients with PH and New York Heart Association class III-IV symptoms were treated with bosentan, 62.5 mg twice daily, for 1 month, which was gradually increased to 125 mg twice daily thereafter. Right heart catheterization (RHC), a clinical evaluation and echocardiographic measurements were performed at baseline and at 4 ± 3 (mean ± SD) months of follow-up. Response to bosentan was defined as an improvement in clinical, echocardiographic and RHC parameters. RESULTS: Six patients did not complete the study (therapy was discontinued due to hypotension, elevated liver enzymes or acute decompensation of HF), 11 patients completed the follow-up; 9 patients responded to therapy. Systemic arterial pressures, pulmonary pressures, PVR and the transpulmonary gradient significantly decreased compared with baseline levels in 9 responders (p = 0.05, 0.05, 0.01 and 0.004, respectively), and 4 became eligible for heart transplantation and 3 for left ventricular assist device implantation. CONCLUSIONS: Bosentan decreased pulmonary pressures and PVR in the majority of patients with PH secondary to systolic HF, thereby allowing them to be considered candidates for heart transplantation.

Detection of early left ventricular and atrial dysfunction in overweight patients with preserved ejection fraction: a speckle tracking analysis.

BACKGROUND: Little remains known about the role of overweight to promote progressive atrial and ventricular myocardial dysfunction. Aim of this study was to investigate the potential influence of overweight on left ventricular (LV) and atrial (LA) function, as assessed by speckle tracking strain analysis, in patients at low-to-moderate global cardiovascular risk. METHODS: Seventy patients presenting 1 or more cardiovascular risk factor, with preserved ejection fraction, were enrolled. Peak atrial longitudinal strain (PALS) and Peak ventricular longitudinal strain (PVLS) were calculated by averaging values observed in all LV or LA segments, in four- and two-chamber views (global PALS and global PVLS), using a commercially available semiautomated two-dimensional (2D) strain software. RESULTS: Global PALS was similar in the 2 groups, while global PVLS was significantly lower in the overweight group as compared to normal weight (-17.2 ± 3.3 vs. -18.7 ± 2.8, P < 0.05). Univariate analysis of correlation showed a significantly correlation between global PALS and PVLS (r = -0.43, P < 0.01), as well as with E/A ratio (r = 0.40, P < 0.01) and with LV mass index (r = -0.34, P < 0.05). In multivariate linear regression analysis, these parameters were confirmed as independent predictors of PALS. CONCLUSION: In subjects at low-to-moderate cardiovascular risk, overweight is a key determinant of the reduction of global LV longitudinal function as assessed by 2D strain.

Reference values of right atrial longitudinal strain imaging by two-dimensional speckle tracking.

BACKGROUND: The role of speckle tracking in the assessment of right atrial (RA) deformation dynamics has not been established yet. The reference ranges of RA longitudinal strain indices were measured by speckle tracking in a population of normal subjects. METHODS: In 84 healthy individuals, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and time to peak longitudinal strain (TPLS) were measured using a six-segment model for the RA. Strain rate (SR) was also measured starting from the QRS-wave onset, peak positive (x-wave), first peak negative (y-wave), and second negative peak (z-wave). The time from the QRS onset was measured to each wave peak. RESULTS: Adequate tracking quality was achieved in 64% of segments analyzed. Inter- and intraobserver variability coefficients of measurements ranged between 6% and 11%. Global PALS was 49 ± 13%, global TPLS was 363 ± 59 msec, x-wave was 2.12 ± 0.58 sec(-1) , y-wave was -1.91 ± 0.63 sec(-1) , and z-wave was -2.18 ± 0.78 sec(-1) . CONCLUSION: Speckle tracking is a feasible technique for the assessment of longitudinal myocardial RA deformation. Reference ranges of strain indices were reported.

Incidence of ventricular arrhythmias after biventricular defibrillator replacement: impact on safety of downgrading from CRT-D to CRT-P.

BACKGROUND: Cardiac resynchronization therapy (CRT) reduces mortality and hospitalizations. It is debated whether CRT alone (CRT-P) or CRT plus defibrillator (CRT-D) is preferable, and still guidelines are not exhaustive. The aim of the study was to investigate whether to implant CRT-P or CRT-D in CRT-D patients who did not experience malignant arrhythmias at the moment of replacement. METHODS: Out of 451 heart failure patients undergoing CRT-D according to guidelines, 103 (67±10 years, 80% men) underwent device replacement with CRT-D. Every 6 months patients underwent to clinical evaluation and device interrogation and episodes of ventricular arrhythmias (VA) stored. At baseline and before replacement echocardiogram was performed. Patients were defined responders if left ventricular (LV) end-systolic volume decreased ≥15% and super-responders if LV ejection fraction increased ≥40% or ≥50%. RESULTS: Mean follow-up was 75±24 months after implantation and 26±10 months after replacement. First VAs incidence per year did not decrease over time (P=0.619). Before replacement, 27 patients (26.2%, 15 responders/12 non-responders) experienced VA. After replacement, 8 patients (7.7%, 4 responders/4 non-responders) experienced VA for the first time. Super-responder condition was not associated with lower VA incidence before (0.499) and after (P=0.339) replacement. At multivariate analysis, age was the only independent predictor of electrical appropriate therapy after substitution (ORper year=1.17; 95% CI: 1.03-1.34; P=0.003). CONCLUSIONS: Freedom from VA before device replacement does not correlate with freedom from VA after replacement, so downgrade from CRT-D to CRT-P is not feasible at replacement, in particular in the elderlies, independently of responder and super-responder condition.

Vascular inflammation in obesity and sleep apnea.

BACKGROUND: Unrecognized obstructive sleep apnea (OSA) is highly prevalent in obesity. Both obesity and OSA are associated with vascular endothelial inflammation and increased risk for cardiovascular diseases. We investigated directly whether the endothelial alterations that are attributed commonly to obesity are in fact related to OSA. METHODS AND RESULTS: Seventy-one subjects with a body mass index ranging from normal to obese underwent attended polysomnography. To assess vascular inflammation and oxidative stress directly, we quantified the expression of nuclear factor-kappaB and nitrotyrosine by immunofluorescence in freshly harvested venous endothelial cells. To evaluate basal endothelial nitric oxide (NO) production and activity, we quantified the expression of endothelial NO synthase (eNOS) and phosphorylated eNOS. Vascular reactivity was measured by brachial artery flow-mediated dilation. Expression of eNOS and phosphorylated eNOS and flow-mediated dilation were significantly lower, whereas expression of nitrotyrosine was significantly greater in OSA patients (n=38) than in OSA-free subjects (n=33) regardless of central adiposity. Expression of nuclear factor-kappaB was greater in obese OSA patients than in obese OSA-free subjects (P=0.004). Protein expression and flow-mediated dilation were not significantly affected by increasing body mass index or central obesity in OSA patients and in OSA-free subjects. After 4 weeks of continuous positive airway pressure therapy, flow-mediated dilation and expression of eNOS and phosphorylated eNOS significantly increased whereas expression of nitrotyrosine and nuclear factor-kappaB significantly decreased in OSA patients who adhered to continuous positive airway pressure >/=4 hours daily. CONCLUSIONS: Untreated OSA rather than obesity is a major determinant of vascular endothelial dysfunction, inflammation, and elevated oxidative stress in obese patients.

Multicenter experience with implantable defibrillators subject to recall.

BACKGROUND: The management of implantable cardioverter defibrillators (ICDs) affected by advisories, which often include generator replacement, is complex and the risk of device failure needs to be carefully assessed for each patient. METHODS: We analyzed the response to the advisory communication in the Italian centers involved in the recall for the Prizm 1861 and Renewal (Boston Scientific-formerly Guidant-St. Paul, MN, USA) communication. RESULTS: One hundred and thirty-nine of 843 Prizm (16.5%) and 458 of 2,342 Renewal devices (19.6%) were explanted. The total incidence over a 4-year time frame of the failure event was equal to zero of 710 (0%) for Prizm ICDs and eight of 2,342 (0.34%) for Renewal ICDs. A limited percentage of devices affected by recall were definitely explanted following the indications stated by the advisory. The failure rates that resulted from analysis of our data (0% for Prizm and 0.34% for Renewal) were inferior to those already found or projected along the device lifetime globally, as reported in the most recent Company Product Performance Report (0.72% for Prizm and 1.83% for Renewal). CONCLUSIONS: In absence of underestimation of the events, a lower incidence than expected could resize the dimension of the problem, justifying the concept of a more frequent follow-up of patient with respect to the choice of an immediate device explant.

Transmural myocardial ischaemia complicating recovery after dobutamine-atropine stress echocardiography in patients with non-significant coronary artery disease: insights from invasive assessment of coronary physiology.

In the proposed selection of cases, traditional imaging is integrated with contemporary diagnostic tools available in the cath-lab to navigate the potential mechanisms underlying a very rare complication occurring in the recovery phase of dobutamine-atropine stress echocardiography. The data, collected in a time frame of nearly 15 years, provide interesting elements to possibly evolve from speculative considerations to plausible confirmation of the candidate pathophysiological mechanism mediating the occurrence of transmural myocardial ischaemia after beta-blockers administration.

Acute and long-term efficacy and safety of sildenafil for the treatment of chronic thromboembolic pulmonary hypertension in a heart transplant recipient.

We report on the successful treatment with sildenafil of a unique case of severe chronic thromboembolic pulmonary hypertension which developed as a late complication in a 71-year-old heart transplant recipient, with focus on the potential therapeutic challenges encountered in the management of such a peculiar association of clinical conditions.

Right atrial speckle tracking analysis as a novel noninvasive method for pulmonary hemodynamics assessment in patients with chronic systolic heart failure.

BACKGROUND: The right atrium (RA) plays multiple roles in the cardiac cycle. The reservoir phase of the RA is a dynamic rather than a static phase of cardiac cycle and RA deformation is dependent on pulmonary pressures exerted on the right ventricle and, therefore, backwards on the RA. The purpose of this study was to assess the accuracy and the clinical applicability of the speckle tracking echocardiography (STE) evaluation of the RA in predicting the invasive systolic pulmonary artery pressure (SPAP) in patients with systolic heart failure (HF) undergoing right heart catheterization (RHC). METHODS: Thirty-one hemodynamically stable, in-clinic HF patients who were undergoing RHC were included. Doppler echocardiography and RHC catheterization were simultaneously performed. Echocardiographic measures and STE where obtained as peak atrial longitudinal strain (PALS), RA strain rate, and time to peak longitudinal strain (TPLS). RA PALS was inversely correlated with invasively assessed SPAP (r =-0.81; P < 0.001) while RA strain directly correlated with SPAP (r = 0.82; P < 0.001). RA PALS and strain rate retained this correlation even after nitroprusside challenge test (r =-0.81; P < 0.001 and r = 0.91; P < 0.001, respectively). Area under the curve optimal cutoffs for predicting the SPAP > 50 mmHg were for RA PALS 10.3% (AUC:0.93, sensitivity: 100%, specificity: 78%). CONCLUSION: RA STE showed a significant correlation with pulmonary pressure. RA assessment with STE can predict pulmonary artery hypertension in HF patients. This result is consistent with nitroprusside challenge test. Although RA STE is not routinely used, its evaluation may implement right heart evaluation in HF patients.

Left ventricular twisting as determinant of diastolic function: a speckle tracking study in patients with cardiac hypertrophy.

PURPOSE: Left ventricular hypertrophy (LVH) can develop in response to training with morphological changes in the heart and to pathological increase in afterload such as in essential hypertension. Deformation analysis using two-dimensional (2D) strain echocardiography can detect early systolic function abnormalities in patients with LVH. The aim of this study was to characterize left ventricular twisting (LVT) modifications, in professional athletes, compared with control subjects and with patients with hypertensive cardiopathy. METHODS: Seventy-six patients were enrolled: 37 professional athletes with cardiac hypertrophy (group A), 22 patients with early hypertensive cardiopathy (group B) cross-matched for LV mass index, and 17 healthy controls (group C), with no evidence of cardiac hypertrophy. All patients had no concomitant cardiac disease. All patients were investigated at rest using transthoracic echocardiography. LVT was obtained with speckle tracking analysis, using dedicated software. RESULTS: LVT was reduced in group A compared to group B and C (group A: 8.0° ± 2.4°; group C: 10.3° ± 2.3°; group B: 16.0° ± 4.2°; P < 0.01). In overall population, LVT showed a significant correlation with transmitral flow pattern (r =-0.58, P < 0.01) and with age (r =-0.57, P < 0.01). LVT showed the best predictive value to diagnose diastolic dysfunction (AUC: 0.86, P < 0.0001). CONCLUSIONS: 2D strain can identify specific patterns of myocardial deformation in professional athletes, controls, and patients with early hypertensive cardiopathy. In our study LVT showed a parallel trend with modifications of diastolic function and could represent a promising tool to differentiate functional cardiac hypertrophy from hypertensive cardiac hypertrophy.

Sleep disordered breathing and arrhythmia burden in pacemaker recipients.

BACKGROUND: Sleep disordered breathing (SDB), a common condition among patients with permanent pacemaker (PM), is associated with greater incidence of cardiac arrhythmias. Scarce availability of sleep laboratories and the high costs of nocturnal-attended polysomnography limit the routine screening of patients with PM for SDB. We investigated whether a novel PM that utilizes variations in transthoracic impedance to record the fluctuations in breathing pattern and minute ventilation could be used to screen patients for SDB. METHODS: Twenty patients who underwent dual-chamber PM implantation were studied. The Talent 3 DR PM (SORIN Group Italy S.r.l., Milan, Italy) calculates apnea-hypopnea index (AHI) by computing minute ventilation signal derived from transthoracic impedance measurements. Within a month after PM implantation, an in-home respiratory monitoring was performed to evaluate the accuracy of PM-derived AHI. Patients were followed for mean ± standard deviation, 487 ± 166 days. The PM was checked at each follow-up visit to retrieve the information about recurrent arrhythmias. RESULTS: Eleven patients were diagnosed with SDB by an in-home respiratory monitoring. An AHI derived from an in-home respiratory monitoring was similar to pacemaker-derived AHI (27 ± 14 vs 16 ± 13 events/hour, P = 0.15). The cumulative incidence of cardiac arrhythmias, including atrial fibrillation, extrasystolic beats, sustained and nonsustained ventricular tachycardia, and supraventricular tachycardia was similar in patients with and without SDB. CONCLUSION: SDB is highly prevalent in patients with permanent pacemaker. Screening for SDB with Talent 3 DR PM may facilitate diagnosis and treatment of SDB.

Left atrial longitudinal strain by speckle tracking echocardiography correlates well with left ventricular filling pressures in patients with heart failure.

BACKGROUND: The combination of early transmitral inflow velocity and mitral annular tissue Doppler imaging (E/Em ratio) is widely applied to noninvasively estimate left ventricular (LV) filling pressures. However E/Em ratio has a significant gray zone and its accuracy in patients with heart failure is debated. Left atrial (LA) deformation analysis by speckle tracking echocardiography (STE) was recently proposed as an alternative approach to estimate LV filling pressures. This study aimed at exploring the correlation of LA longitudinal function by STE and Doppler measurements with direct measurements of LV filling pressures in patients with heart failure. METHODS: A total of 36 patients with advanced systolic heart failure (ejection fraction < or = 35%), undergoing right heart catheterization, were studied. Simultaneously to pulmonary capillary wedge pressure (PCWP) determination, peak atrial longitudinal strain (PALS) and mean E/Em ratio were measured in all subjects by two independent operators. PALS values were obtained by averaging all segments (global PALS), and by separately averaging segments measured in the 4-chamber and 2-chamber views. RESULTS: Not significant correlation was found between mean E/Em ratio and PCWP (R = 0.15). A close negative correlation between global PALS and the PCWP was found (R = -0.81, p < 0.0001). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.93) and excellent sensitivity and specificity of 100% and 93%, respectively, to predict elevated filling pressure using a cutoff value less than 15.1%. Bland-Altman analysis confirmed this close agreement between PCWP estimated by global PALS and invasive PCWP (mean bias 0.1 +/- 8.0 mmHg). CONCLUSION: In a group of patients with advanced systolic heart failure, E/Em ratio correlated poorly with invasively obtained LV filling pressures. However, LA longitudinal deformation analysis by STE correlated well with PCWP, providing a better estimation of LV filling pressures in this particular clinical setting.

Ventricular Preexcitation: An Anomalous Wave Interfering with the Ordered Ventricular Activation.

Ventricular preexcitation is a depolarization of the ventricles that occurs before the conventional sequence, and the electrocardiogram is the specific test for diagnosis. A Kent bundle is the paradigm of ventricular preexcitation, and it is associated with short PR, wide QRS and delta wave. This finding is not always very evident, as it can have different degrees of pre-eccitazione; therefore great diagnostic care must be taken in this field. If not properly identified, the pattern of ventricular preexcitation may lead to an incorrect diagnosis. The methodology of precision electrocardiology is able to confront all these aspects.

Inflammation, oxidative stress, and repair capacity of the vascular endothelium in obstructive sleep apnea.

BACKGROUND: Indirect evidence implicates endothelial dysfunction in the pathogenesis of vascular diseases associated with obstructive sleep apnea (OSA). We investigated directly whether dysfunction and inflammation occur in vivo in the vascular endothelium of patients with OSA. The effects of continuous positive airway pressure (CPAP) therapy on endothelial function and repair capacity were assessed. METHODS AND RESULTS: Thirty-two patients with newly diagnosed OSA and 15 control subjects were studied. Proteins that regulate basal endothelial nitric oxide (NO) production (endothelial NO synthase [eNOS] and phosphorylated eNOS) and inflammation (cyclooxygenase-2 and inducible NOS) and markers of oxidative stress (nitrotyrosine) were quantified by immunofluorescence in freshly harvested venous endothelial cells before and after 4 weeks of CPAP therapy. Vascular reactivity was measured by flow-mediated dilation. Circulating endothelial progenitor cell levels were quantified to assess endothelial repair capacity. Baseline endothelial expression of eNOS and phosphorylated eNOS was reduced by 59% and 94%, respectively, in patients with OSA compared with control subjects. Expression of both nitrotyrosine and cyclooxygenase-2 was 5-fold greater in patients with OSA than in control subjects, whereas inducible NOS expression was 56% greater. Expression of eNOS and phosphorylated eNOS significantly increased, whereas expression of nitrotyrosine, cyclooxygenase-2, and inducible NOS significantly decreased in patients who adhered to CPAP > or = 4 hours daily. Baseline flow-mediated dilation and endothelial progenitor cell levels were lower in patients than in control subjects, and both significantly increased in patients who adhered to CPAP > or = 4 hours daily. CONCLUSIONS: OSA directly affects the vascular endothelium by promoting inflammation and oxidative stress while decreasing NO availability and repair capacity. Effective CPAP therapy is associated with the reversal of these alterations.