The left ventricular outflow tract and carotid artery velocity time integrals.

The left ventricular outflow tract velocity time integral (LVOT VTI) is commonly used in the intensive care unit as a measure of stroke volume (SV) and how the SV changes in response to an intervention; therefore, the LVOT VTI is used to guide intravenous fluid management. Various peripheral Doppler surrogates are proposed to infer the LVOT VTI (e.g., measures from the common carotid artery). A recently-described, novel method of insonation has an excellent ability to detect change in the LVOT VTI. This approach raises important facets of Doppler flow and insonation error, as well as the general principles at play when using a peripheral artery to infer changes from the left ventricle. Relating the VTI of a peripheral artery to the LVOT VTI was recently described mathematically and may help clinicians think about the Doppler relationship between central and peripheral flow.

Quantity and location of aortic valve calcification predicts paravalvular leakage after transcatheter aortic valve replacement: a systematic review and meta-analysis.

Introduction: Transcatheter aortic valve replacement (TAVR) is the first-line treatment for patients with moderate-to-high surgical risk of severe aortic stenosis. Paravalvular leakage (PVL) is a serious complication of TAVR, and aortic valve calcification contributes to the occurrence of PVL. This study aimed to investigate the effect of location and quantity of calcification in the aortic valve complex (AVC) and left ventricular outflow tract (LVOT) on PVL after TAVR. Method: We performed a systematic review and meta-analysis to evaluate the effect of quantity and location of aortic valve calcification on PVL after TAVR using observational studies from PubMed and EMBASE databases from inception to February 16, 2022. Results: Twenty-four observational studies with 6,846 patients were included in the analysis. A high quantity of calcium was observed in 29.6% of the patients; they showed a higher risk of significant PVL. There was heterogeneity between studies (I2 = 15%). In the subgroup analysis, PVL after TAVR was associated with the quantity of aortic valve calcification, especially those located in the LVOT, valve leaflets, and the device landing zone. A high quantity of calcium was associated with PVL, regardless of expandable types or MDCT thresholds used. However, for valves with sealing skirt, the amount of calcium has no significant effect on the incidence of PVL. Conclusion: Our study elucidated the effect of aortic valve calcification on PVL and showed that the quantity and location of aortic valve calcification can help predict PVL. Furthermore, our results provide a reference for the selection of MDCT thresholds before TAVR. We also showed that balloon-expandable valves may not be effective in patients with high calcification, and valves with sealing skirts instead of those without sealing skirts should be applied more to prevent PVL from happening. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=354630, identifier: CRD42022354630.

Intraoperative accurate assessment of septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM).

Surgical restoration of the left ventricular outflow tract (LVOT) is necessary for patients suffering from hypertrophic obstructive cardiomyopathy (HOCM), when symptoms are present despite the administration of medical treatment. One point of great significance during the procedure is the evaluation of the LVOT gradient after completion of septal myectomy. Most physicians choose to measure this value by transesophageal echocardiography (TEE) in combination with the direct measurement with the use of needles inserted into the aorta and left ventricle. In this article, we present the implementation of a new technique to estimate the peak-to-peak pressure gradient between the left ventricle and the aorta intraoperatively using a single double lumen central venous catheter inserted through the antegrade cardioplegia cannulation site across the aortic valve into the left ventricle.

A modified endocardial radiofrequency ablation approach for hypertrophic obstructive cardiomyopathy guided by transthoracic echocardiography: a case series.

BACKGROUND: A series of studies showed that endocardial radiofrequency ablation (ERFA) could reduce the left ventricular outflow tract (LVOT) gradient in patients with septal hypertrophy. This study aimed to determine the safety and efficacy of a modified ERFA approach guided by transthoracic echocardiography (TTE) as an alternative to ablation performed under a three-dimensional (3D) electroanatomical system or intracardiac echocardiography (ICE). METHODS: Twenty-five patients with hypertrophic obstructive cardiomyopathy (HOCM) underwent ERFA of septal hypertrophy, guided by echocardiography. The LVOT gradient, left ventricular ejection fraction (LVEF), LV thickness, New York Heart Association (NYHA) class, and biochemical laboratory values were recorded before ablation and during follow-up. RESULTS: The patients' peak and stress-induced LVOT gradients were significantly reduced after 12 months of follow-up (resting gradient: from 123.2±17.7 to 15.7±7.8 mmHg, P<0.05; provocative gradient: from 140.2±20.8 to 18.4±8.0 mmHg, P<0.05). Compared with baseline, the septal diameter was reduced slightly after 12 months, but the difference was not significant (24.8±3.5 vs. 24.2±3.4 mm, P>0.05). The reduction in LVOT gradient was associated with an improvement in NYHA functional classification (from 3.0±0.0 to 1.6±0.7, P<0.05), the 6-minute walking distance (413±129 m at baseline; 458±108 m immediately after ERFA; 471±139 m after 12 months, P<0.05), and pro B-type natriuretic peptide levels (from 924.00±139 to 137.45 ±75.73 pg/mL, P<0.05). After the procedure, the patients showed no worsening of LVEF compared with baseline (64%±5.3%), and no cases of bundle branch block nor complete heart block occurred. CONCLUSIONS: ERFA guided by TTE provides a new treatment option for HOCM which can achieve symptomatic improvement as well as a significant and sustained reduction of the LVOT gradient. Moreover, by avoiding the use of the 3D electroanatomical system or ICE, this treatment has an acceptable cost.

Magnetic resonance imaging abnormalities in the basal interventricular septum of patients with left ventricular outflow tract arrhythmias.

INTRODUCTION: Concealed structural abnormalities were detected by delayed enhancement - magnetic resonance imaging (DE-MRI) in patients with apparently idiopathic tachycardia of left ventricular (LV) origin. Basal septal fibrosis was evaluated as a potential arrhythmia substrate in patients with left ventricular outflow tract (LVOT) arrhythmias. METHODS AND RESULTS: A total of 22 patients with LVOT arrhythmias, including frequent monomorphic premature ventricular complexes (PVCs) in 15 patients and ventricular tachycardia (VT) in 7 patients, underwent catheter ablation and DE-MRI. A total of 19 patients with frequent PVCs and 17 patients with idiopathic VT of other origin served as a control group. Basal septal intramural fibrosis as thin strip-shaped intramyocardial DE or as marked intramyocardial DE involving >25% of wall thickness was detected more frequently in patients with LVOT arrhythmias (41% and 32%) than in patients with non LVOT arrhythmias (14% and 3%). After successful ablation, 4/16 patients with basal septal intramural fibrosis and LVOT PVCs (n = 3) or LVOT VT (n = 1) compared with no patient without basal septal fibrosis experienced episodes of sustained VT with similar or different QRS morphology resulting in ICD therapy in three patients. Follow-up DE-MRI after PVC ablation (17 ± 7 months) revealed an increase in LV ejection fraction from 49 ± 5% to 56 ± 5% (n = 9) but the amount of septal DE remained unchanged. CONCLUSIONS: Basal septal intramural fibrosis may serve as the arrhythmia substrate in a substantial part of patients with premature ventricular complexes (PVCs) and VT originating from the LVOT and identifies patients with continued risk for VT recurrence after initially successful ablation of LVOT arrhythmias.

Assessment of left ventricular outflow tract and aortic root: comparison of 2D and 3D transthoracic echocardiography with multidetector computed tomography.

AIMS: Accurate echocardiographic assessment of left ventricular outflow tract (LVOT) and the aortic root is necessary for risk stratification and choice of appropriate treatment in patients with pathologies of the aortic valve and aortic root. Conventional 2D transthoracic echocardiographic (TTE) assessment is based on the assumption of a circular shaped LVOT and aortic root, although previous studies have indicated a more ellipsoid shape. 3D TTE and multidetector computed tomography (MDCT) applies planimetry and are not dependent on geometrical assumptions. The aim was to test accuracy, feasibility, and reproducibility of 3D TTE compared to 2D TTE assessment of LVOT and aortic root areas, with MDCT as reference. METHODS AND RESULTS: We examined 51 patients with 2D/3D TTE and MDCT at the same day. All patients were re-examined with 2D/3D TTE on a different day to evaluate 2D and 3D re-test variability. Areas of LVOT, aortic annulus, and sinus were assessed using 2D, 3D TTE, and MDCT. Both 2D/3D TTE underestimated the areas compared to MDCT; however, 3D TTE areas were significantly closer to MDCT-areas. 2D vs. 3D mean MDCT-differences: LVOT 1.61 vs. 1.15 cm2, P = 0.019; aortic annulus 1.96 vs. 1.06 cm2, P < 0.001; aortic sinus 1.66 vs. 1.08 cm2, P = 0.015. Feasibility was 3D 76-79% and 2D 88-90%. LVOT and aortic annulus areas by 3D TTE had lowest variabilities; intraobserver coefficient of variation (CV) 9%, re-test variation CV 18-20%. CONCLUSION: Estimation of LVOT and aortic root areas using 3D TTE is feasible, more precise and more accurate than 2D TTE.

Double pseudoaneurysm, recurrent subvalvular aortic membrane and small left ventricular outflow tract in the same patient: who dares?

Patients with pseudoaneurysm in the left ventricular outflow tract (LVOT) commonly present vague and nonspecific symptoms making the diagnosis difficult. We present the case of a 37-year-old patient with two subvalvular pseudoaneurysms in whom a combined resection surgery, enlargement of the LVOT, aortic valve replacement (AVR) and aortic root replacement were performed using the technique of Cabrol.

Extensive Left Ventricular Myectomy Surgery for Hypertrophic Obstructive Cardiomyopathy / 日本心臓血管外科学会雑誌

<b>[Background] </b>Surgical septal myectomy is the gold-standard therapy for hypertrophic obstructive cardiomyopathy (HOCM) in Europe and America. However, few cases underwent surgical septal myectomy in Japan. We have performed the surgical transaortic extended left ventricular myectomy (LV myectomy) as a first choice in HOCM patients unresponsive to pharmacologic therapy. We report the short and medium term clinical outcomes. <b>Methods</b> : From May 2012 to September 2014, 9 patients underwent extended LV myectomy without other accompanying procedures. All cases were symptomatic and peak left ventricular outflow tract pressure gradients (LVOTG) were 50 mmHg or more. We assessed clinical and echocardiographic outcomes at the short and medium term, intra-operative findings and cardiomyocyte pathological findings. <b>Results</b> : All patients (mean age 64.3 years, 56% female) underwent transaortic LV myectomy with no obvious complications. Postoperative LVOTG were controlled within 10 mmHg or less. SAM disappeared completely in all patients and MR decreased to mild or less. LVOTG sustained good control of 10 mmHg or less under low-dose dobutamine stress echocardiography at the medium term. <b>Conclusion</b> : Our transaortic extended LV myectomy procedure is effective in decreasing LVOTG, SAM and MR with low operative morbidity and mortality.

Left Ventricular Outflow Tract Pseudoaneurysm after Aortic Valve Replacement.

Left ventricular outflow tract pseudoaneurysm is an uncommon complication following aortic valve replacement (AVR), occurring most frequently secondary to endocarditis. We present a case of a 47-year-old female with a history of intravenous drug abuse and a past surgical history of two AVRs (2001 and 2009 with aortic root replacement for endocarditis) who presented with symptoms of lower extremity weakness. Subsequent radiologic imaging revealed the presence of a left ventricular outflow tract pseudoaneurysm, which was surgically managed with a homologous conduit.