Fusion CRT pacing: septal flash significance in super responder patients

Background

LV only CRT pacing is an option that may be considered to maximize response to CRT and at least as an alternative in non-responders to biventricular (BiV) pacing. However, criteria to best titrate therapy on an individual basis are lacking in fusion pacing. On the other hand, septal flash (SF) is a strong predictor of favorable response for patients (pts) with BiV pacing.

Purpose

To analyze the relationship between SF and the response to fusion CRT pacing.

Methods

Consecutive pts with exclusive fusion CRT-P were included. Right atrium/left ventricle leads DDD CRT pacing system were used in all patients. Prospective data were collected at every 6 months follow-up visits: device interrogation, exercise test, echocardiographic parameters. Exercise tests, device reprogramming and medication optimization were performed regular in order to maximize CRT response. Patients were divided in 2 groups: super-responders (SR) and responders (R). SRs were defined those with left ventricular end-systolic volume (LVESV) improvement ≥30% and stable ejection fraction (LVEF) ≥45%.

Results

69 pts with NYHA II–III heart failure and non-ischemic dilated cardiomyopathy were initially included. 5 pts were non responders and excluded (non LBBB, spontaneous QRS <149 ms). Final analyzed group had 64 pts (35 male) aged 60±12 y.o. The mean follow-up was 54±19 months; 22 pts (34%) were SRs. At baseline, SF was found in all SR pts and in 55% of R pts. SF was corrected post CRT in all patients, except one. For this patient (LV lead in a posterior branch of the coronary sinus – CS) the strategy included an upgrade to triple chamber device with a second lead in a lateral branch of the CS and became SR from R. Mitral regurgitation decreased in 38 patients (all SR, 40% R). Interesting, baseline left atrium volume and pulmonary sistolic artery pressure were smaller in SR versus R group, however SF did not corelate with LA volume/diastolic dysfunction.

Conclusions

Septal flash seems to be a strong predictor of super-response in patients with fusion CRT pacing. This finding could improve the selection of candidates for fusion CRT-P, however larger studies are needed to assess SF in this categories of patients.

Funding Acknowledgement

Type of funding sources: None.

Relationship between oxidative stress and three-dimensional echocardiographic changes in myxomatous mitral valves with severe regurgitation - a pilot study

Funding Acknowledgements

Type of funding sources: None.

Background. Reactive oxygen species (ROS) have been reported to contribute to the molecular pathogenesis of severe mitral regurgitation induced by myxomatous degeneration. Data about oxidative stress and the possible relationship with the extent of prolapsing and/or flail elements is scarce in the literature. The pathogenic mechanism may prompt the development of therapeutic approaches aimed at delaying extensive valvular alteration.

Purpose. The aim of the study is to investigate the possible correlation between ROS expression in myxomatous mitral valves with severe regurgitation and the extent of valvular alteration.

Material and methods. Samples from myxomatous mitral valves with ruptured chordae and severe regurgitation were harvested during surgical intervention for valve repair/replacement from 9 patients. Besides transthoracic echocardiography, all patients were evaluated before surgery by transesophageal echocardiography (TEE) with three-dimensional (3D) reconstruction of the mitral valve, using 3D zoom mode acquisition with qualitative and quantitative analysis through the 4D Auto MVQ technology. Tissue from the valvular samples was further analysed for the assessment of ROS by 2 methods: spectrophotometry (ferrous oxidation xylenol orange - FOX assay) and confocal microscopy (dihydroethidium staining).

Results. Patients had a mean age of 51.88 ± 13.54 years, with a left ventricular ejection fraction of 62.55 ± 7.33%, left ventricular end-diastolic diameter of 5.4 ± 0.72cm and end-diastolic volume of 168.55 ± 62.57ml, a mitral annulus area of 17.91 ± 5.74 cm2 and a number of prolapsing/flail scallops varying between 1 and 5 (average of 2 ± 1 scallops). All patients had diffuse thickening of the mitral leaflets with at least one primary and one secondary ruptured chordae and flail of the P2 scallop. Two patients had significant prolapse of at least 2 anterior mitral leaflet scallops and three patients had supplemental significant prolapse and/or flail of at least 1 posterior scallop, besides flail of P2. The mean value for ROS in the valvular tissue was 9.46 ± 2.03nM H2O2/mg tissue/h at FOX assay. A significant positive correlation between the ROS values and the extent of prolapsing/flail segments was found (R = 0.67, p = 0.04).

Conclusion. Besides the diagnosis and accurate preoperatory valve description, 3D TEE along with molecular investigations contribute to the understanding of myxomatous mitral valves’ pathogenesis. Oxidative stress increased in the mitral valves with advanced myxomatous degeneration. Whether this occurs as a cause or a consequence contributing to the disease progression as well as the sources of ROS are worth further investigation.

Monoamine oxidase contributes to the valvular oxidative stress in patients with mitral valve regurgitation

Background

Oxidative stress plays a central role in the pathogenesis of cardiovascular diseases but the role of enzymatic sources of reactive oxygen species (ROS) remains elusive. There is scarce information in the literature regarding valvular oxidative stress. Monoamine oxidases (MAOs), with 2 isoforms, A and B, have emerged as important sources of oxidative stress in the cardiovascular system.

Purpose

To assess whether MAOs-related oxidative stress occurs in the pathological valves in patients with severe mitral regurgitation (due to valve degeneration and chordae rupture) and surgical indication and its interference with the activation of the renin-angiotensin aldosterone (RAAS) system.

Material and methods

Samples of mitral valve (n=17) were harvested during the valvular replacement procedure and used for reactive oxygen species (ROS) assessment (immune-fluorescence, spectrophotometry) and MAO mRNA and protein expression (qPCR and immune-fluorescence) measurement. Inflammatory markers, biochemical parameters and echocardiography (GE, Vivid 9, Vivid E95) data were also collected.

Results

Both MAO isoforms are expressed in the diseased mitral valves, with a predominance of MAO-A isoform. Ex vivo incubation with angiotensin 2 (12 h, 100 nM) of samples obtained from patients without RAAS medication lead to MAO upregulation and high ROS production. MAO-related oxidative stress was mitigated by MAO inhibition with clorgyline (MAO-A inhibitor, 10 microM) and selegyline (MAO-B inhibitor, 10 microM) and also by the angiotensin II receptor type 1 (AT1) antagonist, irbersartan (10 microM).

Conclusions

Monoamine oxidase is expressed in the pathological mitral valves, regardless the etiology. Its expression and the related-oxidative stress are modulated by angiotensin 2, irbesartan. Whether the latter effect is present in valvular patients treated with RAAS inhibitors is currently under investigation.

Funding Acknowledgement

Type of funding sources: None.

Diastolic dyssynchrony in patients with LV only fusion pacing CRT without RV lead

Funding Acknowledgements

Type of funding sources: None.

Background

CRT improves both systolic and diastolic function, thus increasing cardiac output. However, less data is available concerning diastolic dyssynchrony and fusion pacing CRT. The aim of our study was to assess the outcome of LV diastolic asynchrony in a population of fusion pacing CRT without right ventricular (RV)  lead.

Methods

Prospective data were collected from a cohort of patients (pts) with right atrium/left ventricle leads (RA/LV CRT). Baseline and every 6 months follow-up included standard ETT and classical dyssynchrony parameter measurements. Diastolic dyssynchrony was done by offline speckle-tracking derived TDI timing assesment of the simultaneity of E" and A"  basal septal and lateral wall 4 chamber view. New parameters were introduced: E" and respectively A" time (E"T / A"T) as the time difference between E" (respectively A" ) peaks septal and lateral wall. Exercise tests, drugs optimization and device individual programmimg were systematically performed in order to maintain constant fusion and improve CRT response. Patients were divided in three groups: super-responders (SR), responders (R) and non responders (NR).

Results

Sixty-two pts (35 male) aged 62 ± 11 y.o. with idiopathic DCM implanted with a RA/LV CRT were analyzed: 34%SR / 61%R / 5%NR. Baseline initial characteristics: QRS 164 ± 18 ms; EF 27 ± 5.2; 29% had type III diastolic dysfunction (DD), 63% type II DD, 8% type I DD. Average follow-up was 45 ± 19 months; mean LVEF at the last follow-up was 37 ± 7.9%. The E"T decreased from 90 ± 20 ms to 25 ± 10 ms in SR with significant LV reverse remodelling (LV end-diastolic volume 193.7 ± 81 vs 243.2 ± 82 ml at baseline, p < 0.0028) and lower LV filling pressures (E/E" 13.2 ± 4.6 vs 11.4 ± 4.5, p =0.0295). DD profile improved in 65% of R with a reduction in E/A ratio (1.46 ± 5.3 vs. 0.82 ± 3.9 at baseline, p= 0.4453). Non-sudden cardiac death occurred in 3 NR pts (2%) with type III DD, severe LA volume and larger E" T /A"T (E"T> 85 msec A"T > 30 msec).  Significant cut off value calculated by ROC curve for LV diastolic dyssynchrony is E"T > 80 ms and A"T of > 25 msec.

Conclusions

Fusion pacing CRT without RV lead showed a positive outcome; improving LV diastolic dyssynchrony in responders and super-responders patients is obvious. Larger randomized studies are needed to define the role of diastolic asynchronism as a predictor of favorable response in fusion pacing.

Abstract Figure. Typical TDI patterns in LV fusion pacing

P1168Redefining first degree AV block: constant fusion pacing CRT is easier in longer PR interval patients

Background

LV only pacing is non-inferior to BiV pacing, and recent publications showed that DDD CRT without RV lead is safe in patients with normal atrioventricular (AV) conduction, although there are no device algorithms available for fusion pacing and PR interval variability is understudied in this population. Purpose: To analyse AV behaviour in pts with DDD CRT and the impact to effective fusion maintenance.

Methods

Consecutive pts with right atrium/left ventricle (RA/LV) DDD CRT pacing system were included. Prospective data were collected at every 6 months follow-up visits: device interrogation, exercise test (ET), echocardiography. CRT assessment during ET analysed loss of LV capture with special focus on maintaining constant fusion pacing during exercise. We defined 2 groups of pts: longer PR interval pts (200-250 ms) and normal PR interval pts (˂200 ms). In case of LV loss of capture or unsatisfactory LV fusion pacing, device reprogramming was performed individualised for each patient and BB/ivabradine dose titration was done to achieve stability of PR spontaneous interval. Patients were rescheduled in no later one month to be reassessed by ET.

Results

55 pts (29 male) aged 62 ± 11 y.o. were included, 36 pts with normal PR and 19 pts with longer PR. During follow-up (45 ± 19 months), a total of 235 ETs were performed with mean exercise load 118 ± 35 watts. In the normal PR group 14 pts (39%) had inadequate pacing or loss of LV capture during ET due to physiological shortening of PR interval vs. 4 pts (21%) in the long PR group. Loss of LV capture by exceeding maximum tracking rate (MTR) was noted in 6 pts (17%) with normal PR vs. 2 pts (11%) with longer PR. Post ET device optimisation included:  reprogramming rate adaptive AV interval (23 ± 8 ms decrease in normal PR pts vs. 12 ± 7 ms in longer PR pts, p < 0.0001) and individualised programming of MTR. BB/ivabradine optimisation was performed in 32% of pts with normal PR vs. 13% of pts with longer PR.

Conclusions

A lower rate of optimisations after exercise test was needed in pts with a slightly longer AV conduction to achieve stability of fusion pacing DDD CRT without device algorithms. Larger studies are needed to assess AV conduction variability and the benefits of fusion pacing CRT in pts with longer PR interval.

Abstract Figure.

416 LV only fusion pacing CRT without RV lead induces size and shape LA reverse remodelling

Background

Adaptive CRT pacing induces significant left atrium (LA) reverse remodelling comparing to biventricular (BiV) pacing, although the algorithm delivers compulsory BiV pacing in heart rate over 100/min! Purpose: to assess LA remodelling in LV only pacing without RV lead in a real-life situation of permanent CRT fusion pacing.

Methods

Prospective data were analysed from a cohort of patients with CRT-P indication implanted with right atrium/left ventricle (RA/LV) DDD pacing system. Complete follow-up at every 6 months included device interrogation, exercise test, transthoracic echocardiography (TE) and individualised drug optimisation. LA evaluation included: parasternal dimension (LAd), 4 chambers view: mid-LA transverse diameter (LAt), basal LA maximal transverse diameter (LAb); volume (LA vol) and shape assessment: trapezoidal LA shape was defined by LAt less than Lab, the reverse situation was considered ellipsoidal shape.

Results

55 pts (30 males) with idiopathic DCM aged 62 ± 11 y.o. were included. Baseline characteristic: QRS 164 ± 18 ms; EF 27 ± 5.2%; mitral regurgitation was severe in 22 pts, moderate in 27 pts and mild in 6 pts; 15 pts had type III diastolic dysfunction, 37 pts with type II diastolic dysfunction, 3 pts with type I diastolic dysfunction. Average follow-up was 42 ± 18 months: all patients were responders, EF increased at 37 ± 7.9%; mitral regurgitation decreased in 38 pts (69%), diastolic profile improved in 36 pts (65%). Trapezoidal LA shape was documented in 31 (56%) patients. Atrial fibrillation was noted in 4 pts (7%) and cardioversion was needed. Non-sudden cardiac death occurred in 5 patients (9%), all deaths were noted in pts with severe LA vol, trapezoidal shape and type III diastolic dysfunction. Statistically significative LA reverse remodelling was noted regarding LA volume, but not shape.

Conclusions

RA/LV fusion CRT pacing was associated with important LA reverse remodelling and a low incidence of AF. Larger randomised studies are needed to validate these results and assess the role of LA shape remodelling in CRT.

before RA/LV CRT-P Follow-up 42 ± 18 months p LV EF, %, mean ± SD 27 ± 5.2 37 ± 7.9 <0.0001 LA diameter (mm), mean ± SD 50 ± 4.9 44 ± 2.8 <0.0001 LA area (cm2), mean ± SD 24 ± 5.6 22 ± 0.7 0.0138 LA volume (ml), mean ± SD 104.9 ± 34 80 ± 28.2 0.0001

Abstract 416 Figure.

An enhanced method for accessory pathway localization in case of Wolff-Parkinson-White syndrome

This paper presents an analysis of the Arruda accessory pathway localization method for patients suffering from Wolff-Parkinson-White syndrome, with modifications to increase the overall accuracy. The Arruda method was tested on a total of 79 cases, and 91.1% localization performance was reached. After a deeper analysis of each decision point of the Arruda localization method, we considered that the lead aVF was not as relevant as other leads (I, II, III, V1) used. The branch of the decision tree, which evaluates the left ventricle positions, was entirely replaced using different decision criteria based on the same biological parameters. The modified algorithm significantly improves the localization accuracy in the left ventricle, reaching 94.9%. An accurate localization performance of non-invasive methods is relevant because it can enlighten the necessary invasive interventions, and it also reduces the discomfort caused to the patient.

Echocardiographic evidences of increased left ventricular pressure and atrial dilatation in patients with drug-resistant paroxystic atrial fibrillation and structurally normal heart

Global myocardial index (GMI) has been significantly related to left ventricular filling pressure. We hypothesized that GMI and echographic indicators of atrial dilatation were significantly different in pAF pts compared to normals.

METHODS

39 patients (pts) without structural heart disease, aged 52+/-10 years with pAF were compared to 36 control-matched pts aged 48+/-16 years. Following parameters were assessed: P-wave duration (Pd), GMI, left atrial dimensions (LAd=M-mode, parasternal, LAt and LAI are measurements of short and long-axis apical four chamber view), surface (LAs), volume (LAv), total ejection fraction (LA EF), right atrial dimension (RAd) and surface (RAs), total atrial surface (TAs=LAs+RAs). LAv was calculated using ellipse formula pi/6 (LAdxLAlxLAt).

RESULTS

There was no difference between the 2 groups concerning Pd (p=0.1), LA EF (p=0.23), LAd (p=0.08) and LAt (p=0.06) while the rest of the parameters were significantly higher in pAF pts: GMI: 0.5+/-0.17 vs 0.36+/-0.06 (p=0.001); LAI: 5.4+/-0.5 vs 4.5+/-0.3 cm2 (p=0.001); LAs was founded increased in pAF pts (20.6+/-5.7 vs 16.3+/-2.1 cm2, p=0.001); TAs: 40.6+/-6.9 vs 30.6+/-5.1 cm2, p=0.0001; LAv: 51.6+/-10.4 vs 37.2+/-9.3 ml (p=0.0001).

CONCLUSIONS

Although apparently without structural heart disease, pAF pts presented evidence of increased filling pressions in left ventricle and indirect markers of atrial stretch. The role of increased intra-atrial pressure in pts pFA and predictive value of these parameters need to be evaluated in a larger number of patients.

Absence of correlation between QRS duration and echographic parameters of ventricular desynchronization. Can we still trust the electrocardiographic criteria?

The aim of the study was to assess if echographic ventricular desynchronization parameters measured in patients with dilated cardiomyopathy (DCM) and severe heart failure are correlated with the duration of the QRS on surface electrocardiogram.

METHODS

This study included 51 pts aged 58.8 +/- 7.4 years with idiopathic DCM. The following parameters were measured: QRS duration; effective contraction time (ECT) measured as the interval between QRS onset and closure of aortic valve, interventricular delay (IVD) measured as the time between onset of aortic and pulmonary flow, left ventricular mechanical delay (LVD) as the time from maximal interventricular septum contraction and posterior wall contraction, posterior (P), lateral (L) and posterolateral (PL) wall delays, as the time from QRS onset to maximal wall contraction. Regional postsystolic contraction was defined in a given wall as the difference (contraction delay - ECT)> 50ms.

RESULTS

29 pts presented complete LBBB, 22 pts had QRS duration < 120 ms. 39 pts had a postsystolic contraction of the PL wall (32 pts of the L wall and 26 pts of the P wall). 16 pts with QRS duration <120 had a postsystolic contraction of the PL wall (as for the LBBB the rest of 39 pts). In 40 pts the sequence of regional ventricular contraction was: P-L-PL wall (16 pts with QRS<120). LVD was > 100 ms in 36 pts (26 pts with LBBB and 10 with QRS<120). 27 of pts with LBBB and 6 with QRS <120 ms presented IVD> 30ms. There was no correlation between the QRS duration and the parameters listed above.

CONCLUSIONS

In DCM pts there is no correlation between the duration of the QRS and echocardiographic parameters of ventricular desynchronization. Mechanical ventricular de-synchrony can be observed in patients with QRS duration < 120 ms.

Global myocardial index in patients with multisite pacing

Global myocardial index (GMI) is a sensitive echocardiographic indicator of overall cardiac function. The aim of this study was to compare the GMI changes induced by Bi-V pacing to the variations in clinical, electrocardiographic and echocardiographic parameters currently used for evaluation of ventricular resynchronization in order to test the potential marker of positive clinical response.

PATIENTS AND METHODS

This study included 35 consecutive patients (pts), aged 65.7+/-7.5 years, implanted with an endocavitary Bi-V pacemaker for drug refractory severe heart failure. NYHA class was evaluated before implantation and at day 30. QRS duration (QRSd), echocardiographic interventricular delay (IVD), and GMI were determined in the paced and non-paced situation at day 1, 7 and 30 after implantation.

RESULTS

NYHA class improved from 3.5+/-0.3 to 2.4+/-0.4 (p<0.01). GMI improved significantly (p<0.0001) after Bi-V in all pts from 1.25 +/- 0.5 to 0.77 +/- 0.34 and remained stable all along the study. GMI decrease (dGMI) in pts with NYHA functional class improvement > 0.5 was 0.52 +/- 0.16while dGMI in pts with NYHA functional class improvement < or = 0.5 was 0.21+/- 0.19. dGMI was statistically correlated with IVD shortening (r=0.67, p<0.0001) but not with QRSd shortening.

CONCLUSION

The GMI improves during Bi-V pacing, mostly in responders pts and the improvement remains unchanged after the implant. The GMI decrease induced by Bi-V pacing is correlated with the IVD shortening and NYHA functional class improvement.

The value of intermittent inotropic therapy in unhospitalized patients with refractory heart failure

The treatment of intractable heart failure (New York Heart Association--NYHA IV) with inotropic support is a well established adjunct in the control of clinical status of end-stage heart failure patients but usually needs many admissions and a long period of hospitalization. In this study we report on the follow-up findings of 64 patients for 18 months who were seen in an outpatients congestive heart failure program. All patients had their full standard oral drug treatment, received intensive patient teaching and weekly inotropic infusions. We assess the effects of this comprehensive therapeutic approach on: 1) the number of hospital admissions, 2) length of stay and 3) the number of emergency room visits during the ensuing year. These data were compared with similar data from the year before entry in the program for each patient. All our patients showed NYHA class IV heart failure and received dobutamine to manage their chronic heart failure in an outpatient setting. The cause of heart failure was ischaemic in 34 (53.12%), idiopathic in 14 (21.87%), hypertension in 10 (15.62%), pulmonary hypertension in 7 (10.93%) and valvular heart disease in 6 (9.37%) patients. The mean period of observation was 382 days. For the period before entry in the program patients had 67 emergency room visits, 184 admissions, and 832 days spent in the hospital. After enrollment all these figures significantly decreased (p<0.001), patients heading 35 emergency room visits, 112 admissions and 518 days spent in the hospital. In conclusion, the intermittent inotropic therapy as an outpatient setting may be a valuable cost-effective therapeutic method, in patients with refractory heart failure and is associated with the reduction of emergency room visits, admissions and days spent in the hospital.

Complete atrioventricular block in patients with acute inferior myocardial infarction. Clinical spectrum and prognostic significance

Patients with acute inferior myocardial infarction (IMI) and complete atrioventricular block (CAVB) have a wide range of mortality rate. This raises the question whether there is no other risk factor that interferes in this particular situation. In our study, mortality rate in patients with acute IMI and CAVB was significantly greater than in patients without conduction disturbance, but the occurrence of right ventricle myocardial infarction (RVMI) enhanced the mortality rate regardless of the presence or absence of CAVB.