Best Practices in Left Ventricular Pacing for Transcatheter Aortic Valve Replacement.

Transcatheter aortic valve replacement (TAVR) is continually evolving, with a recent emphasis on a "minimalist" approach toward reducing procedural invasiveness, duration, and recovery time. Whereas a better understanding of the relationship between TAVR and new conduction disturbances has led to improved periprocedural management, intraprocedural rapid-pacing techniques have not evolved beyond traditional right ventricular temporary pacing. An alternative strategy utilizing the left ventricular guidewire for rapid pacing has been developed with evidence supporting its safety, effectiveness, and potential reductions in procedure time and cost. This review will outline the current best practices in left ventricular pacing for TAVR, a practical technique that embraces the minimalist approach to TAVR and may be considered for routine use. It aims to explore the current evidence and combine this with expert opinion to offer a strategy for temporary pacing that encourages efficiencies for physicians and patients without compromising periprocedural safety.

Transcatheter Aortic Valve Replacement Outcomes in End-Stage Renal Disease Patients on Hemodialysis Requiring Midodrine.

Background: Patients with dialysis-dependent end-stage renal disease (ESRD) taking midodrine may be at high risk for poor outcomes following transcatheter aortic valve replacement (TAVR). We evaluated dialysis-dependent ESRD patients taking midodrine. Methods: We conducted a retrospective analysis of non-clinical trial TAVR patients from February 2012 to December 2020 from 11 facilities in a Western US health system. Patient groups included ESRD patients on midodrine before TAVR (ESRD [+M]), ESRD patients without midodrine (ESRD [-M]), and non-ESRD patients. The endpoints of 30-day and 1-year mortality were represented by Kaplan-Meier survival estimator and compared by log-rank test. Results: Forty-five ESRD (+M), 216 ESRD (-M), and 6898 non-ESRD patients were included. ESRD patients had more comorbid conditions, despite no significant difference in predicted Society of Thoracic Surgeons mortality risk between ESRD (+M) and ESRD (-M) (8.7% vs. 9.2%, p = 0.491). Thirty-day mortality was significantly higher for ESRD (+M) patients vs. ESRD (-M) patients (20.1% vs. 5.6%, p = 0.001) and for ESRD (+M) vs. non-ESRD patients (2.5%, p < 0.001). One-year mortality trended higher for ESRD (+M) vs. ESRD (-M) patients (41.9% vs. 29.8%, p = 0.07), and was significantly higher for ESRD (+M) vs. non-ESRD patients (10.7%, p < 0.001). Compared to ESRD (-M), ESRD (+M) patients had a higher incidence of 30-day stroke (6.7% vs. 1.4%, p = 0.033), 30-day vascular complications (6.7% vs. 0.9%, p = 0.011), and a lower rate of discharge to home (62.2% vs. 84.7%, p < 0.001). In contrast, ESRD (-M) patients had no significant differences from non-ESRD patients for these outcomes. Conclusions: Our experience suggests ESRD patients on midodrine are a higher acuity population with worse survival after TAVR, compared to ESRD patients not on midodrine. These findings may help with risk stratification for ESRD patients undergoing TAVR.

Use of intravascular ultrasound to guide endovascular repair of popliteal artery aneurysms.

OBJECTIVES: To evaluate the outcomes of intravascular ultrasound (IVUS) directed endovascular exclusion of popliteal artery aneurysm (PAA) using stent grafts. METHODS: Clinical data of seven patients who underwent endovascular exclusion of PAA using IVUS guidance between 2009 and 2011 were retrospectively analyzed. Outcome measures included graft patency, endoleak, and clinical symptoms. RESULTS: A total of seven patients were treated with Viabahn stent grafts using IVUS guidance. No patients were lost to follow-up (mean 12 ± 2 months). Patients had an average of two vessel runoff at the end of the procedure. All patients were symptom free with patent stents and no evidence of endoleak at follow-up. CONCLUSIONS: Use of IVUS during endovascular treatment of PAA allows the physician to fully appreciate the anatomy of PAA, including location and extent of thrombus burden and the diameter and location of desired landing zones for appropriate sealing of the aneurysm proximally and distally. IVUS-guided treatment is associated with excellent outcomes and does not increase procedural radiation and contrast load.

Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization.

For the diagnosis of atherosclerosis, biomedical imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed. The combined use of IVUS and OCT is hypothesized to remarkably increase diagnostic accuracy of vulnerable plaques. We have developed an integrated IVUS-OCT imaging apparatus, which includes the integrated catheter, motor drive unit, and imaging system. The dual-function imaging catheter has the same diameter of current clinical standard. The imaging system is capable for simultaneous IVUS and OCT imaging in real time. Ex vivo and in vivo experiments on rabbits with atherosclerosis were conducted to demonstrate the feasibility and superiority of the integrated intravascular imaging modality.

New echocardiography-based classification of mitral valve pathology: relevance to surgical valve repair.

A new echocardiography-based classification of mitral valve pathology is proposed, the adoption of which may provide a uniform approach to the assessment of individual cases by the cardiologist, cardiac anesthesiologist, and surgeon. This type of approach may facilitate the planning and execution of valve repair techniques, with higher rates of success than are currently reported.

Integrated intravascular optical coherence tomography (OCT) - ultrasound (US) catheter for characterization of atherosclerotic plaques in vivo.

A miniature integrated intravascular optical coherence tomography (OCT) - ultrasound (US) catheter for real-time imaging of atherosclerotic plaques has been developed, providing high resolution and deep tissue penetration at the same time. This catheter, with an outer diameter of 1.18mm, is suitable for imaging in human coronary arteries. The first in vivo 3D imaging of atherosclerotic microstructure in a rabbit abdominal aorta obtained by an integrated OCT-US catheter is presented. In addition, in vitro imaging of cadaver coronary arteries were conducted to demonstrate the imaging capabilities of this integrated catheter to classify different atherosclerotic plaque types.

Cardiac magnetic resonance imaging: infarct size is an independent predictor of mortality in patients with coronary artery disease.

BACKGROUND: Cardiac magnetic resonance imaging (CMR) can accurately determine infarct size. Prior studies using indirect methods to assess infarct size have shown that patients with larger myocardial infarctions have a worse prognosis than those with smaller myocardial infarctions. OBJECTIVES: This study assessed the prognostic significance of infarct size determined by CMR. METHODS: Cine and contrast CMR were performed in 100 patients with coronary artery disease (CAD) undergoing routine cardiac evaluation. Infarct size was determined by planimetry. We used Cox proportional hazards regression analyses (stepwise forward selection approach) to evaluate the risk of all-cause death associated with traditional cardiovascular risk factors, symptoms of heart failure, medication use, left ventricular ejection fraction, left ventricular mass, angiographic severity of CAD and extent of infarct size determined by CMR. RESULTS: Ninety-one patients had evidence of myocardial infarction by CMR. Mean follow-up was 4.8±1.6 years after CMR, during which time 30 patients died. The significant multivariable predictors of all-cause mortality were extent of myocardial infarction by CMR, extent of left ventricular systolic dysfunction, symptoms of heart failure, and diabetes mellitus (P<.05). The presence of infarct greater than or equal to 24% of left ventricular mass and left ventricular ejection fraction less than or equal to 30% were the most optimal cut-off points for the prediction of death with bivariate adjusted hazard ratios of 2.11 (95% confidence interval 1.02-4.38) and 4.06 (95% confidence interval 1.73-9.54), respectively. CONCLUSIONS: The extent of myocardial infarction determined by CMR is an independent predictor of death in patients with CAD.

Access platform techniques for transcatheter aortic valve replacement.

BACKGROUND: One of the unique variables for successful implantation of transcatheter aortic valves involves the ability to secure an access route for deployment of the aortic valve. AIM OF STUDY: A large number of the high-risk patients with critical aortic stenosis referred for transcatheter valve implantation approach may not be candidates for the femoral approach due to peripheral vascular disease with the morbidity and mortality increased severalfold in patients who develop access related complications. METHOD & RESULTS: A thorough knowledge and review of various alternate access site techniques and trouble shooting are therefore important and required by the implanting cardiac surgeons involved in transcatheter aortic valve therapy. CONCLUSION: The article review highlights the various percutaneous, hybrid, and surgical access techniques platforms available as well as options for implantation of these devices.

The cardiovascular hybrid room a key component for hybrid interventions and image guided surgery in the emerging specialty of cardiovascular hybrid surgery.

The last few years has seen a paradigm shift in the treatment of cardiovascular related diseases from once traditional open surgical modalities to the entire cardiovascular tree being amenable to percutaneous interventions. The tremendous advances in transcatheter endovascular procedures currently being applied to the heart and the peripheral vasculature have resulted in a treatment paradigm shift in the care of the cardiovascular patient. These changing winds in the treatment of cardiovascular disease require that a new type of cardiovascular specialist, code-named the cardiovascular hybrid surgeon, be trained to perform and provide seamless care in providing both endovascular as well as open surgical procedures to this increasingly complex group of patients.

Multidetector computed tomography shows intramyocardial fat deposition.

BACKGROUND: Intramyocardial fat deposition occurs as an age-related process and in multiple pathologic processes. OBJECTIVE: We evaluated the presence of left ventricular (LV) and right ventricular (RV) intramyocardial fat with 64-slice multidetector computed tomography (MDCT). METHODS: One hundred persons with no history of coronary artery disease (47 women, 53 men; mean age [+/- SD], 53 +/- 12.2 years) and 25 patients with CT findings of myocardial infarction (17 men, 8 women; mean age, 71.3 +/- 9.6 years) were studied for intramyocardial fat in defined segments of the ventricles (17 LV and 10 RV segments) at 3 levels. Fat deposition was defined as density range of -30 to -190 Hounsfield units on images both before and after contrast. RESULTS: In healthy persons, LV intramyocardial fat was primarily located in the basal segments (5% anteroseptal, 5% inferior), and RV intramyocardial fat was primarily located in the anterolateral (24% of base, 23% of mid) and inferolateral (27% base, 27% mid) segments. Older age was associated with an increased odds of RV (sex-adjusted odds ratio [OR] per decade increment, 1.61; 95% confidence interval [CI], 1.11-2.33; P = 0.012) but not LV (OR, 0.97; 95% CI, 0.67-1.40; P = 0.85) intramyocardial fat. Compared with women, men had a lower risk of LV (95% CI, 0.1-0.64; P = 0.004) but not RV (95% CI, 0.35-1.87; P = 0.62) intramyocardial fat. Patients with old myocardial infarction (>3 years) had increased percentage of fat in infarcted left ventricles at all 3 levels (P

Imaging of patent foramen ovale with 64-section multidetector CT.

PURPOSE: To investigate the feasibility of 64-section multidetector computed tomography (CT) by using CT angiography (a) to demonstrate anatomic detail of the interatrial septum pertinent to the patent foramen ovale (PFO), and (b) to visually detect left-to-right PFO shunts and compare these findings in patients who also underwent transesophageal echocardiography (TEE). MATERIALS AND METHODS: In this institutional review board-approved HIPAA-compliant study, electrocardiographically gated coronary CT angiograms in 264 patients (159 men, 105 women; mean age, 60 years) were reviewed for PFO morphologic features. The length and diameter of the opening of the PFO tunnel, presence of atrial septal aneurysm (ASA), and PFO shunts were evaluated. A left-to-right shunt was assigned a grade according to length of contrast agent jet (grade 1, 1 cm to 2 cm; grade 3, >2 cm). In addition, 23 patients who underwent both modalities were compared (Student t test and linear regression analysis). A difference with P < .05 was significant. RESULTS: A flap valve, seen in 101 (38.3%) patients, was patent at the entry into the right atrium (PFO) in 62 patients (61.4% of patients with flap valve, 23.5% of total patients). A left-to-right shunt was detected in 44 (16.7% of total) patients (grade 1, 61.4%; grade 2, 34.1%; grade 3, 4.5%). No shunt was seen in patients without a flap valve. Mean length of PFO tunnel was 7.1 mm in 44 patients with a shunt and 12.1 mm in 57 patients with a flap valve without a shunt (P < .0001). In patients with a tunnel length of 6 mm or shorter, 92.6% of the shunts were seen. ASA was seen in 11 (4.2%) patients; of these patients, a shunt was seen in seven (63.6%). In 23 patients who underwent CT angiography and TEE, both modalities showed a PFO shunt in seven. CONCLUSION: Multidetector CT provides detailed anatomic information about size, morphologic features, and shunt grade of the PFO. Shorter tunnel length and septal aneurysms are frequently associated with left-to-right shunts in patients with PFO.

Right atrial cavotricuspid isthmus: anatomic characterization with multi-detector row CT.

PURPOSE: To retrospectively evaluate the anatomic characteristics of the right atrial cavotricuspid isthmus (CTI) by using 64-section multi-detector row computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval and waiver of informed consent were obtained for this HIPAA-compliant study. The anatomic region of the CTI was evaluated in 201 patients (116 men and 85 women; mean age, 58 years +/- 11 [standard deviation]) who underwent coronary multi-detector row CT. CTI length was assessed along three parallel isthmic levels (paraseptal, central, and inferolateral). Central isthmus depth was classified as straight (3 mm), concave (>3 to 5 mm). Measurements were obtained during three cardiac phases: midsystole, middiastole, and atrial contraction. Subthebesian recess dimensions and eustachian ridge width were measured. Distances from the atrioventricular node artery to the coronary sinus, from the right coronary artery (RCA) to the inferior vena cava, and from the RCA to the tricuspid valve annulus were measured. Software was used for statistical analysis. RESULTS: At middiastole, the paraseptal isthmus (mean length, 20 mm +/- 3.5; range, 11-34 mm) was significantly shorter than the central isthmus (24 mm +/- 4.3; range, 12-43 mm) and the central isthmus was shorter than the inferolateral isthmus (27 mm +/- 4.8; range, 13-45 mm) (P < .001). The longest CTI measurements were obtained during midsystole, and the shortest were obtained during atrial contraction (40% variation per cardiac cycle). Isthmus contraction occurred primarily in the posterior segment of the central isthmus (RCA to inferior vena cava distance). At middiastole, the central isthmus was straight in 8% of patients, concave in 47% of patients, and pouchlike (>5 mm) in 45% of patients. The mean depth was greater during atrial contraction (6.3 mm +/- 2.1) than in midsystole (4.3 mm +/- 1.5) and middiastole (5.1 mm +/- 1.8) (32% variation during cardiac cycle). A subthebesian recess greater than 5 mm deep was identified in 45% of patients. In 24% of patients, a thick eustachian ridge greater than 4 mm was seen. The atrioventricular node artery passed close to the coronary sinus wall (mean distance, 2.1 mm +/- 0.7; range, 1-6 mm). CONCLUSION: Cardiac multi-detector row CT provides extensive information regarding the size and morphology of the CTI and its related structures.

Tricuspid valve disease.

The normal tricuspid valve anatomy and function have several dissimilarities to the corresponding mitral valve in the left heart, in part, based on lower pressures in the right heart chambers. The functional abnormalities resulting from tricuspid valve disease are classified as primary and secondary. Primary valve disease is any associated intrinsic valve pathology. The list of responsible conditions includes congenital, rheumatic, infective endocarditis, carcinoid heart disease, toxic effects of chemicals, tumors, blunt trauma, and myxomatous degeneration. The secondary tricuspid valve disease does not involve intrinsic anatomic abnormalities of the valve apparatus, aside from tricuspid annular dilation secondary to right ventricular dilation and dysfunction. The most common cause of tricuspid valve disease is secondary to left heart disease, either myocardial, valvular, or mixed. Although bedside diagnosis of advanced tricuspid valve disease is feasible, echocardiography provides valuable clues to the presence and severity of tricuspid valve stenosis and/or regurgitation with considerable accuracy. The tricuspid regurgitation signal using Doppler techniques is utilized for estimation of right ventricular systolic pressure, which, in the absence of right ventricular outflow obstruction, corresponds to pulmonary arterial systolic pressure. This is clinically useful since nearly 80 to 90% of patients exhibit some degree of tricuspid regurgitation. The treatment of tricuspid valve disease is guided by underlying etiology and pathology. Tricuspid valve repair is increasingly advocated for patients with advanced tricuspid regurgitation, especially when combined with surgery on the left heart pathology. Primary tricuspid valve disease is often treated by surgical approach specific to the underlying pathology.

Arterial supply to sinuatrial and atrioventricular nodes: imaging with multidetector CT.

PURPOSE: To retrospectively evaluate the depiction of anatomic characteristics of the arterial supply to the sinuatrial node (SAN) and the atrioventricular node (AVN) with 64-section computed tomography (CT). MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study; informed consent was not required. Anatomic origin, number, course, and variants of the arteries to the SAN and AVN were examined with coronary multidetector CT in 102 patients (55 men, 47 women; mean age, 57 years +/- 13 [standard deviation]). Known accessory blood supplies to the AVN, including left and right Kugel anastomotic arteries, were investigated. Possible extension of the first septal perforating artery to the AVN was evaluated. Univariate and bivariate statistical data were reported. Means +/- standard deviations, 95% confidence intervals, and percentages were calculated. RESULTS: A single sinuatrial nodal artery originated from the proximal 40 mm of the right coronary artery (RCA) in 67 and from the proximal 35 mm of the left circumflex (LCX) artery in 28 patients. A dual blood supply to the SAN was seen in six patients. The sinuatrial nodal artery was not visualized in one patient. An S-shaped variant was seen in 18% of left sinuatrial nodal arteries and invariably traveled posteriorly in the sulcus between the left superior pulmonary vein and left atrial appendage. The sinuatrial nodal artery approached the nodal tissue by one of three routes-retrocaval (47.5%), precaval (42.6%), or pericaval (9.9%). The AVN was supplied by the RCA in 89 patients, the LCX artery in 11 patients, and by both arteries in two patients. Two left and six right Kugel anastomotic arteries were detected as supplying the AVN area. The first septal perforating artery had no detectable connection to the AVN. CONCLUSION: The arterial blood supply to the SAN and the AVN is variable and can be imaged with multidectector CT. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/2461070030/DC1.

Impact of intraoperative echocardiography/surgery team on successful mitral valve repair: a community hospital experience.

BACKGROUND AND AIM OF THE STUDY: Mitral valve (MV) repair is generally accepted as the preferred treatment of mitral regurgitation (MR) with MV prolapse secondary to myxomatous mitral valve disease (MMVD). However, the incidence of successful valve repair is variable between hospitals and among different surgeons at one hospital, and often results in needless MV replacement. The study aim was to measure the impact of a dedicated echocardiography/surgery team on MV repair at a community hospital. METHODS: The outcome was analyzed of a group of 116 consecutive patients with severe MR secondary to MMVD who underwent surgery by the same surgeon over a six-year period. A dedicated team approach, comprising one echocardiographer and one surgeon was established in January 1999. The results of MV repair between 1996 and 1998 (group I; n = 37) were compared to results obtained between 1999 and 2001 (group II; n = 79). RESULTS: In group I, MV repair was attempted in 25 patients (67.6%) and was successful in 21 (56.8%). In group II, MV repair was attempted in 68 patients (86.1%) and was successful in 67 (84.8%). The success rate between groups was significantly (p = 0.001) different. The rate of successful MV repair in patients with a diffusely redundant prolapsing valve involving both leaflets and multiple segments with chordae elongation was significantly higher in group II (14/20; 70%) than in group I (1/6; 14.3%) (p = 0.011). CONCLUSION: A greater incidence of successful MV repair, even with more diffuse pathology of MMVD, was realized following the institution of dedicated echocardiography/surgery team at a community hospital. It is proposed that a combination of dedicated intraoperative echocardiography and surgical expertise is required for optimal results in MV repair.