Occurrence of persistent atrial fibrillation during pacing for sinus node disease: The influence of His bundle pacing versus managed ventricular pacing.

INTRODUCTION: In patients with sinus node disease (SND), the dual-chamber pacemaker (PM) is programmed in DDDR mode with an algorithm to avoid unnecessary right ventricular (RV) pacing. This pacing mode may prolong PR interval with consequently atrioventricular (AV) asynchrony which is associated with a higher risk of atrial fibrillation (AF). We evaluate whether preserving AV synchrony by setting a fixed AV delay during physiological RV pacing, that is, His bundle pacing (HBP), could reduce the risk of AF occurrence in comparison with a standard pacing mode with an algorithm to avoid unnecessary RV pacing (DDD-VPA). METHODS AND RESULTS: We collected retrospective data from 313 consecutive patients who had undergone PM for SND. The first occurrence of persistent AF (>7 consecutive days) as a function of the pacing mode was evaluated. HBP and DDD-VPA were implemented in 82 and 231 patients, respectively. Persistent AF occurred in 128 (40.9%) patients over a median follow-up of 70 months (67-105). The DDD-VPA pacing mode was significantly correlated with the occurrence of persistent AF only when the basal PR was long (>180 ms). The risk of persistent AF was significantly lower in patients on HBP than in those on DDD-VPA, adjusted HR = .57 (95% CI, .36- .89, p=.014). Other independent predictors of persistent AF occurrence were: A history of AF (HR = 3.91; 95% CI, 2.48-6.19, p = .001), age, and long PR interval (HR = 2.98; 95% CI, 2.00-4.43, p=.001). CONCLUSION: In SND patients and long basal PR interval, the HBP may reduce the risk of persistent AF in comparison with the DDD-VPA.

Patients with right bundle branch block and concomitant delayed left ventricular activation respond to cardiac resynchronization therapy.

Aims: Right bundle branch block (RBBB) typically presents with only delayed right ventricular activation. However, some patients with RBBB develop concomitant delayed left ventricular (LV) activation. Such patients may show a specific electrocardiographic (ECG) pattern resembling RBBB in the precordial leads in association with an insignificant S-wave in lateral limb leads (atypical RBBB). We therefore postulated that the ECG pattern of atypical RBBB might be able to identify a subgroup of patients likely to respond to cardiac resynchronization therapy (CRT). The purpose of this study was to assess the impact of RBBB ECG morphology on CRT response in patients with heart failure (HF). Methods and results: We evaluated the echocardiographic clinical response of 66 patients with RBBB treated with CRT and followed up for almost 2 years. The patients were divided electrocardiographically into 2 groups: 31 with typical RBBB and 35 with atypical RBBB. Responders were classified in terms of reduction in LV end-systolic volume index (ESVi) ≥ 15% or reduction in the New York Heart Association (NYHA) Class ≥ 1 or Packer score variation (NYHA response with no HF-related hospitalization events or death). The atypical RBBB group presented a longer LV activation time compared with the typical RBBB group (111.9 ± 17.6 vs. 73.2 ± 15.4 ms; P < 0.001). In the atypical and typical RBBB groups, respectively, 71.4% and 19.4% of patients were ESVi responders (P = 0.001) 74.3% and 32.3% were NYHA responders (P = 0.002); similarly, 71.4% and 29.0% of patients exhibited a 2-year Packer score of 0 (P = 0.002). Conclusion: Patients with atypical RBBB, which is a pattern highly suggestive of concomitant delayed LV conduction, may show a satisfactory response to CRT.

TIMI Risk Index as a Predictor of 30-Day Outcomes in Patients With Acute Pulmonary Embolism.

BACKGROUND: Available studies have already identified age, heart rate (HR) and systolic blood pressure (SBP) as strong predictors of early mortality in acute pulmonary embolism (PE). MATERIAL AND METHODS: One-hundred-seventy patients, with acute PE confirmed on computed tomography angiography (CTA) were enrolled. Thrombolysis In Myocardial Infarction (TIMI) risk index (TRI) was calculated using the formula [heart rate (HR) x (AGE/102)/ systolic blood pressure (SBP)]. Study outcomes were 30-day mortality and/or clinical deterioration. RESULTS: Receiver operating characteristics (ROC) curve revealed that a TRI ≥45 was highly specific for both outcomes (AUC 0.91, 95% CI 0.83-0.98, p<0.0001) with a positive predictive value (PPV) and negative predictive value (NPV) of 8.3 and 96% for 30-day mortality while PPV and NPV for 30-day mortality and/or clinical deterioration were 21.1 and 98.2%, respectively. Multivariate regression analysis showed that TRI ≥45 was an independent predictor of 30-day mortality (O.R. 22.24, 95% CI 2.54-194.10, p=0.005) independently from positive cTnI and RVD (O.R. 9.57, 95% CI 1.88-48.78, p=0.007; OR 24.99, 95% CI 2.84-219.48, p=0.004). Similarly, 30-day mortality and/or clinical deterioration was predicted by TRI ≥45 (O.R. 11.57, 95% CI 2.36-56.63, p=0.003) and thrombolysis (3.83, 95% CI 1.04-14.09, p=0.043), independently from age, RVD and positive cTnI. Cox regression analysis confirmed the role of TRI as independent predictor for both outcomes. Mantel-Cox analysis showed that after 30-day follow-up there was a statistically significant difference in the distribution of survival between patients with and without TRI ≥45 [log rank (Mantel-Cox) chi-square 17.04, p<0.0001]. CONCLUSIONS: Thrombolysis In Myocardial Infarction (TIMI) risk index (TRI) predicted both 30-days mortality (all-causes) and/or clinical deterioration in patients with acute PE.

Changing of Left Atrial Function Index in Symptomatic Patients with Patent Foramen Ovale After Device Closure.

BACKGROUND: Left atrial function is impaired in patients with patent foramen ovale. This study aimed to evaluate the role of left atrial function index in monitoring the course of left atrial function in a patient with patent foramen ovale before and after percutaneous closure. METHODS: We retrospectively reviewed the findings of consecutive patients evaluated in our tertiary center for patent foramen ovale closure to identify those subjects with acute ischemic stroke, transient ischemic attack, or radiological evidence of cerebral ischemic events (index event) who performed a complete echocardiography evaluation reporting evidence of patent foramen ovale between September 2004 and September 2018. The left atrial function was evaluated at baseline and then yearly using the left atrial function index. RESULTS: The cohort of 448 consecutive patients (mean age 43.4 ± 10.4 years, 257 males) was divided into 2 groups according to the temporal window between the index event and patent foramen ovale closure, defined as <1-year (216 patients) and ≥1-year (232 patients). Patients treated within 1 year from the index event maintained similar parameters of left atrial function and left atrial function index over the time, also after the interventional procedure. Conversely, patients treated after 1 year demonstrated a significant reduction of left atrial emptying function and maximal left atrial volume (P < .001 for all) compared to the basal values. The same parameters slightly increased after the percutaneous closure during the second year without reaching the basal values. CONCLUSIONS: Left atrial function index can be used as a non-invasive marker of atrial dysfunction severity in patients with patent foramen ovale before and after the interventional procedure.

General anaesthesia for external electrical cardioversion of atrial fibrillation: experience of an exclusively cardiological procedural management.

AIMS: External electrical cardioversion (EC) usually requires brief general anaesthesia involving anaesthetists. The aim of this study was to evaluate the feasibility and safety of inducing anaesthesia for EC of atrial fibrillation (AF) exclusively by the cardiologic team with anaesthetists on-hand. METHODS AND RESULTS: A retrospective analysis of 624 elective EC, over a 6-year period, was made. No patients were excluded due to the severity of pathology or comorbidities. The protocol of the intravenous anaesthesia was 5 mg bolus of midazolam and subsequent increasing doses of propofol starting from 20 mg to achieve the desired sedation level. After delivering DC shock, a direct observation period followed in order to assess the post-sedation recovery and to detect the procedure-related complications. Electrical cardioversion was effective in 98.9% of the cases. General anaesthesia was effective in 100% of cases with a dosage of propofol, ranging between 20 mg to a maximum of 80 mg, after 5 mg of midazolam was administered. All patients generally showed a fast recovery waking up in a few minutes. The anaesthesiology team was never called for assistance. All the procedures were carried out by the cardiologic team as planned. No thrombo-embolic and allergic complications were observed. Arrhythmic complications were uncommon and essentially bradyarrhythmias. CONCLUSION: A general anaesthesia for outpatient EC of AF can be safely handled by a cardiologist having adequate experience with anaesthetical agents. Moreover, the association of midazolam and a very small dosage of propofol, given their synergic action, is effective and safe in inducing anaesthesia. Arrhythmic complications are rare and limited to bradyarrhythmias.

The QR-max index, a novel electrocardiographic index for the determination of left ventricular conduction delay and selection of cardiac resynchronization in patients with non-left bundle branch block.

Non-left bundle branch block (non-LBBB) remains an uncertain indication for cardiac resynchronization therapy (CRT). Non-LBBB includes right bundle branch block (RBBB) and non-specific LV conduction delay (NSCD), two different electrocardiogram (ECG) patterns which are not generally considered to be associated with LV conduction delay as judged by the invasive assessment of the Q-LV interval. We evaluated whether a novel ECG interval (QR-max index) correlated with the degree of LV conduction delay regardless of the type of non-LBBB ECG pattern, and could, therefore, predict CRT response. In 173 non-LBBB patients on CRT (92 NSCD, 81 RBBB), the QR-max index was measured as the maximum interval from QRS onset to R-wave offset in the limb leads. The correlation between QR-max index and Q-LV interval and the impact of the QR-max index on time to first heart failure hospitalization during 3-year follow-up were assessed. Q-LV correlated better with the QR-max index than with QRSd, particularly in the RBBB group (r = 0.91; p < 0.001 vs. r = 0.19; p < 0.089), while the correlations were r = 0.79 (p < 0.01) and r = 0.68 (p < 0.01), respectively, in the NSCD group. In both groups, the QR-max index was significantly more able than QRSd to identify CRT responders (AUC 0.825 vs. 0.576; p = 0.0008 in RBBB; AUC 0.738 vs. 0.701; p = 0.459 in NSCD). A QR-max index exceeding a cutoff value of 120 ms was associated with CRT response, with predictive values of 86.8 and 81.4% in RBBB and NSCD, respectively. The QR-max index reflects the degree of LV electrical delay regardless of QRS duration in RBBB and NSCD patients and is a useful indicator of suitability for CRT in non-LBBB patients.

Long-Term Clinical Outcomes of Isolated Ostial Left Anterior Descending Disease Treatment: Ostial Stenting Versus Left Main Cross-Over Stenting.

BACKGROUND: The optimal strategy for treating ostial left anterior descending coronary artery (LAD) disease remains matter of speculation. We evaluated the impact on long-term outcomes of ostial LAD disease treated by means of ostial stenting (the floating-stent) or left main (LM)-to-LAD cross-over stenting. METHODS: Clinical and instrumental records of 74 consecutive patients with isolated ostial LAD disease, enrolled between the 1st January 2012 and the 1st January 2017 were reviewed. Patients have been stratified according the stenting techniques adopted: ostial stenting (OS) or LM cross-over (CO). RESULTS: Seventy-four consecutive patients (54 males, mean age 73.39 ±â€¯9.54 years old) have been analyzed. In CO patients the SYNTAX score (16.2 ±â€¯3.3 vs 24.1 ±â€¯2.5, p < 0.0001) and the percentages of rotablation resulted higher than in OS group. IVUS has been predominantly used in CO groups revealing a significant extension of plaque burden of at least 10 mm of LM proximal to the LAD ostium in all the 18 out of 21 patients (85.7%) undergone IVUS-guided procedure. Fluoroscopy time and contrast medium volume were higher in OS versus CO group of patients. On a mean follow-up of 49.7 ±â€¯7.9 months, MACE and target vessel revascularization (TVR) were 21.0% and 21.0% in OS groups versus 10.1 and 5.6% in the CO group (p = 0.20 and p = 0.04, respectively). Restenosis was higher in the OS than in CO group of patients and was located angiographically at the ostium. CONCLUSIONS: On long-term follow-up CO seems to be superior to OS technique for isolated ostial LAD disease especially in the presence of heavy calcification.

Systemic thrombolysis in haemodynamically unstable pulmonary embolism: The earlier the better?

INTRODUCTION: The temporal window for the administration of systemic thrombolysis (ST) in acute pulmonary embolism (PE) has not yet been clarified. We assessed the relationship between short-term cardiovascular (CV) mortality and time of ST administration. MATERIAL AND METHODS: Among 394 consecutive patients admitted between January 2010 and June 2017 with a confirmed PE, we retrospectively review the clinical and instrumental data of those labelled as high-risk PE (n = 76, 41 males, mean aged 64.7 ±â€¯9.1 years old). RESULTS: A receiving operating curve (ROC) analysis established the optimal temporal threshold for the administration of the ST, in respect to the 30-day CV mortality at 8.5 h from the symptom onset (Area under Curve 0.79 ±â€¯0.6, 95% CI 0.73-0.86, p < 0.0001). Mantel-Cox analysis showed that there was a significant difference in the distribution of survival between patients treated within 8.5 h from the beginning of symptoms onset to those treated after 8.6 h [log rank (Mantel-Cox) chi-square 9.68 p = 0.002]. Cox-regression analysis demonstrated that the administration of ST after 8.6 h from the symptom's onset was an independent predictor of 30-day CV mortality in high-risk PE patients (HR 7.81, 95% CI 1.84-33.05, p = 0.005), independently from the occurrence of major bleeding events (HR 5.89, 95% CI 1.38-25.13, p = 0.01), previous CAD (HR 3.31, 95& CI 1.07-10.231. p = 0.03), RV/LV ratio after 2 h from the administration ST > 1 (HR (12.91, 95% CI 3.04-54.77, p = 0.001) and PAH at discharge (HR 3.86, 95% CI 2.22-4.68, p = 0.002). CONCLUSIONS: ST administered within 8.5 h from symptoms onset may be associated with a reduced 30-day CV mortality in high-risk PE patients.

Left atrial enlargement as a maker of significant high-risk patent foramen ovale.

Left atrial (LA) enlargement is a marker of LA cardiopathy and, in patients with patent foramen ovale (PFO), is associated with an increased risk of ischemic stroke. The primary study outcome was the comparison of LA diameter between patients undergoing percutaneous PFO closure versus those treated conservatively. The secondary endpoints were the association of LA diameter with the Risk of Paradoxical Emboli (ROPE) score and the presence of Atrial septal aneurysm (ASA) and Right-To-Left Shunt (RLS). Retrospective analysis of clinical and instrumental data of 1040 subjects referred to a single tertiary center for PFO evaluation and treatment. Seven hundred and nineteen patients were enrolled: 495 patients (closure group, mean RoPE score 7.6 ± 0.8) underwent PFO closure while 224 patients (control group, mean RoPE score 4.1 ± 0.9. p < 0.001) were left to medical therapy. Preoperative LA diameter was significantly larger in closure group and reduced from 44.3 ± 9.1 to 37.3 ± 4.1 mm (p = 0.01) 1 year after the procedure to the size of controls. A larger LA diameter was associated with permanent RLS, RLS curtain pattern, ASA presence and multiple ischemic brain lesions pattern at neuroimaging. A LA diameter ≥ 43 mm was a predictor a RoPEscore > 7. In our patients' cohort, LA diameter was associated with the clinic severity of PFO and RLS. The reversal of LA enlargement after PFO closure suggests a role for RLS to induce LA cardiopathy. LA enlargement has the potential to be considered per se as an indication to transcatheter PFO repair.

Modified balloon aortic valvuloplasty in fragile symptomatic patients unsuitable for both surgical and percutaneous valve replacement.

BACKGROUND: Balloon Aortic valvuloplasty (BAV) is considered as a bridge therapy to percutaneous valve implantation or a palliative treatment in patients with aortic valve stenosis (AVS). Potential risk of complications, in particular in fragile patients, is still not negligible. AIM: To describe the technique and outcomes of modified BAV in fragile symptomatic patients unsuitable for other treatments using no-pacing and minimally invasive approach. METHODS: Symptomatic fragile patients with severe aortic valve stenosis judged unsuitable by the heart team for surgical or percutaneous valve implantation from 1 September 2013 to 1 September 2017 were offered modified BAV. Simplified procedural protocol included a 4F right radial artery access for gradient check, a 8F compatible undersized balloons, two partial inflations-trial before a full inflation with no-pace maker back-up, final pressure gradient recording and aortography. RESULTS: Thirty-four symptomatic fragile patients (mean age 80.9±4.9, range 73 to 91years, 100% Katz >6, mean Euroscore I 30.0±11.7%) underwent modified BAV in the last 5years with immediate success in all (100%). Mean aortic valve area increased from 0.58±0.2cm2 to 1.1±0.2cm2 (p<0.01) whereas mean peak gradient decreased from 75.6±11.3 to 35.8±11.2mmHg (p<0.01). Procedural complications were 14.7%. Thirty-day mortality was 11.8%. On a mean follow up of 38.4±4.6months four patients successfully repeated the procedure, while global mortality was 23.5% (8 patients). The other 22 patients maintained a NYHA class of 2.1±0.7. CONCLUSIONS: No-pacing minimally invasive BAV seems to have acceptable outcomes in patients with severe AVS and no other treatment options.

Hemodynamic comparison of different multisites and multipoint pacing strategies in cardiac resynchronization therapies.

PURPOSE: In order to increase the responder rate to CRT, stimulation of the left ventricular (LV) from multiple sites has been suggested as a promising alternative to standard biventricular pacing (BIV). The aim of the study was to compare, in a group of candidates for CRT, the effects of different pacing configurations-BIV, triple ventricular (TRIV) by means of two LV leads, multipoint (MPP), and multipoint plus a second LV lead (MPP + TRIV) pacing-on both hemodynamics and QRS duration. METHODS: Fifteen patients (13 male) with permanent AF (mean age 76 ± 7 years; left ventricular ejection fraction 33 ± 7%; 7 with ischemic cardiomyopathy; mean QRS duration 178 ± 25 ms) were selected as candidates for CRT. Two LV leads were positioned in two different branches of the coronary sinus. Acute hemodynamic response was evaluated by means of a RADI pressure wire as the variation in LVdp/dtmax. RESULTS: Per patient, 2.7 ± 0.7 veins and 5.2 ± 1.9 pacing sites were evaluated. From baseline values of 998 ± 186 mmHg/s, BIV, TRIV, MPP, and MPP-TRIV pacing increased LVdp/dtmax to 1200 ± 281 mmHg/s, 1226 ± 284 mmHg/s, 1274 ± 303 mmHg, and 1289 ± 298 mmHg, respectively (p < 0.001). Bonferroni post-hoc analysis showed significantly higher values during all pacing configurations in comparison with the baseline; moreover, higher values were recorded during MPP and MPP + TRIV than at the baseline or during BIV and also during MPP + TRIV than during TRIV. Mean QRS width decreased from 178 ± 25 ms at the baseline to 171 ± 21, 167 ± 20, 168 ± 20, and 164 ± 15 ms, during BIV, TRIV, MPP, and MPP-TRIV, respectively (p < 0.001). CONCLUSIONS: In patients with AF, the acute response to CRT improves as the size of the early activated LV region increases.

[Central venous catheter-related right atrial thrombosis in a patient with Hodgkin's lymphoma]. / Trombosi atriale destra correlata a catetere venoso centrale in un paziente con linfoma di Hodgkin.

Central venous catheters (CVC) are commonly used in clinical practice. Although long-term complications are uncommon, catheter-related right atrial thrombosis is a rare but potentially life-threatening one. The optimal management is still controversial. We report the case of a young woman affected by Hodgkin lymphoma with CVC-related right atrial thrombosis diagnosed during routine echocardiography. After initial anticoagulation treatment, she complicated with pulmonary embolism, and the mass was surgically removed via a minimally invasive approach with right minithoracotomy access. Surgery was well tolerated, without complications and with prompt recovery. This case confirms how CVC can lead to thrombosis in the right atrium and how this complication can rapidly deteriorate. Moreover, the possible treatment options for the successful management of this complication are discussed, along with the available literature, showing the advantages of a minimally invasive approach.

Optimization of left ventricular pacing site plus multipoint pacing improves remodeling and clinical response to cardiac resynchronization therapy at 1 year.

BACKGROUND: Approximately one-third of the patients with heart failure (HF) treated with cardiac resynchronization therapy (CRT) fail to respond. Positioning the left ventricular (LV) pacing lead in the area of the latest electrical delay may improve the response to CRT. Multipoint pacing (MPP) of the LV has been shown to improve the acute hemodynamic response. OBJECTIVE: The purpose of this study was to test the hypothesis that patients treated with MPP in whom LV pacing location is optimized have better long-term clinical outcomes than do patients treated with conventional CRT. METHODS: We evaluated the echocardiographic and clinical response of 110 patients with HF treated for nearly 1 year with either conventional CRT (standard [STD] group, n = 54, 49%), CRT with hemodynamic and electrical optimization of the LV pacing site (optimized [OPT] group, n = 36, 33%), or OPT combined with MPP (OPT + MPP group, n = 20, 18%). Responders were classified in terms of reduction in end-systolic volume index ≥15%, reduction in New York Heart Association (NYHA) class ≥1, and Packer score variation (NYHA response with no HF-related hospitalization events or death). RESULTS: In STD, OPT, and OPT + MPP groups, 56%, 72%, and 90% of patients, respectively, were end-systolic volume index responders (P = .004) and 67%, 78%, and 95% were NYHA class responders (P = .012); 59%, 67%, and 90% of patients exhibited a 1-year Packer score of 0 (P = .018). These trends remained significant after adjustment for confounding factors by multivariate logistic analysis. CONCLUSION: Combining MPP with optimal positioning of the LV lead on the basis of electrical delay and hemodynamics enhances reverse remodeling and improves clinical outcomes beyond the effect due to conventional CRT.

ECG parameters predict left ventricular conduction delay in patients with left ventricular dysfunction.

BACKGROUND: Estimating left ventricular electrical delay (Q-LV) from a 12-lead ECG may be important in evaluating cardiac resynchronization therapy (CRT). OBJECTIVE: The purpose of this study was to assess the impact of Q-LV interval on ECG configuration. METHODS: One hundred ninety-two consecutive patients undergoing CRT implantation were divided electrocardiographically into 3 groups: left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific intraventricular conduction delay (IVCD). The IVCD group was further subdivided into 81 patients with left (L)-IVCD and 15 patients with right (R)-IVCD (resembling RBBB, but without S wave in leads I and aVL). The Q-LV interval in the different groups and the relationship between ECG parameters and the maximum Q-LV interval were analyzed. RESULTS: Patients with LBBB presented a long Q-LV interval (147.7 ± 14.6 ms, all exceeding cutoff value of 110 ms), whereas RBBB patients presented a very short Q-LV interval (75.2 ± 16.3 ms, all <110 ms). Patients with an IVCD displayed a wide range of Q-LV intervals. In L-IVCD, mid-QRS notching/slurring showed the strongest correlation with a longer Q-LV interval, followed, in decreasing order, by QRS duration >150 ms and intrinsicoid deflection >60 ms. Isolated mid-QRS notching/slurring predicted Q-LV interval >110 ms in 68% of patients. The R-IVCD group presented an unexpectedly longer Q-LV interval (127.0 ± 12.5 ms; 13/15 patients had Q-LV >110 ms). CONCLUSION: Patients with LBBB have a very prolonged Q-LV interval. Mid-QRS notching in lateral leads strongly predicts a longer Q-LV interval in L-IVCD patients. Patients with R-IVCD constitute a subgroup of patients with a long Q-LV interval.

Multipoint pacing by a left ventricular quadripolar lead improves the acute hemodynamic response to CRT compared with conventional biventricular pacing at any site.

BACKGROUND: Response to cardiac resynchronization therapy (CRT) remains challenging. Pacing from multiple sites of the left ventricle (LV) has shown promising results. OBJECTIVE: The purpose of this study was to systematically compare the acute hemodynamic effects of multipoint pacing (MPP) by means of a quadripolar lead with conventional biventricular (BiV) pacing. METHODS: Twenty-nine patients (23 men; mean age 72 ± 12 years; LV ejection fraction 29% ± 7%; 15 with ischemic cardiomyopathy, 17 with left bundle branch block; mean QRS 183 ± 23 ms) underwent CRT implantation. Per patient, 3.2 ± 1.2 different veins and 6.3 ± 2.4 pacing sites were tested. LV electrical delay (Q-LV) was measured at each location, along with the increase in LV dP/dtmax (maximum rate of rise of LV pressure) obtained by BiV and MPP. The effect of MPP, by means of simultaneous pacing from distal and proximal dipoles, was investigated at all available sites. RESULTS: Overall, 3.2 ± 1.2 different MPP measurements were collected per patient. When all sites were considered, LV dP/dtmax increased from 951 ± 193 mm Hg/s at baseline to 1144 ± 255 and 1178 ± 259 mm Hg/s on BiV and MPP, respectively. When the best site was considered, LV dP/dtmax increased from a baseline value of 942 ± 202 mm Hg/s to 1200 ± 267 mm Hg/s (BiV) and 1231 ± 267 mm Hg/s (MPP). The mean QRS duration at any site during MPP and conventional CRT was 171 ± 18 and 175 ± 16 ms (P = .003), respectively. CONCLUSION: Compared with BiV pacing at any LV site, MPP yielded a small but consistent increase in hemodynamic response. A correlation between the increase in hemodynamics and Q-LV on MPP was observed for all measurements, including those taken at the best and worst sites. The MPP-induced improvement in contractility was associated with significantly greater narrowing of the QRS complex than conventional BiV pacing.