Imaging in Pulmonary Vascular Disease-Understanding Right Ventricle-Pulmonary Artery Coupling.

The right ventricle (RV) and pulmonary arterial (PA) tree are inextricably linked, continually transferring energy back and forth in a process known as RV-PA coupling. Healthy organisms maintain this relationship in optimal balance by modulating RV contractility, pulmonary vascular resistance, and compliance to sustain RV-PA coupling through life's many physiologic challenges. Early in states of adaptation to cardiovascular disease-for example, in diastolic heart failure-RV-PA coupling is maintained via a multitude of cellular and mechanical transformations. However, with disease progression, these compensatory mechanisms fail and become maladaptive, leading to the often-fatal state of "uncoupling." Noninvasive imaging modalities, including echocardiography, magnetic resonance imaging, and computed tomography, allow us deeper insight into the state of coupling for an individual patient, providing for prognostication and potential intervention before uncoupling occurs. In this review, we discuss the physiologic foundations of RV-PA coupling, elaborate on the imaging techniques to qualify and quantify it, and correlate these fundamental principles with clinical scenarios in health and disease. © 2022 American Physiological Society. Compr Physiol 12: 1-26, 2022.

All Roads Lead to Rome: Diverse Etiologies of Tricuspid Regurgitation Create a Predictable Constellation of Right Ventricular Shape Changes.

Introduction: Myriad disorders cause right ventricular (RV) dilation and lead to tricuspid regurgitation (TR). Because the thin-walled, flexible RV is mechanically coupled to the pulmonary circulation and the left ventricular septum, it distorts with any disturbance in the cardiopulmonary system. TR, therefore, can result from pulmonary hypertension, left heart failure, or intrinsic RV dysfunction; but once it occurs, TR initiates a cycle of worsening RV volume overload, potentially progressing to right heart failure. Characteristic three-dimensional RV shape-changes from this process, and changes particular to individual TR causes, have not been defined in detail. Methods: Cardiac MRI was obtained in 6 healthy volunteers, 41 patients with ≥ moderate TR, and 31 control patients with cardiac disease without TR. The mean shape of each group was constructed using a three-dimensional statistical shape model via the particle-based shape modeling approach. Changes in shape were examined across pulmonary hypertension and congestive heart failure subgroups using principal component analysis (PCA). A logistic regression approach based on these PCA modes identified patients with TR using RV shape alone. Results: Mean RV shape in patients with TR exhibited free wall bulging, narrowing of the base, and blunting of the RV apex compared to controls (p < 0.05). Using four primary PCA modes, a logistic regression algorithm identified patients with TR correctly with 82% recall and 87% precision. In patients with pulmonary hypertension without TR, RV shape was narrower and more streamlined than in healthy volunteers. However, in RVs with TR and pulmonary hypertension, overall RV shape continued to demonstrate the free wall bulging characteristic of TR. In the subgroup of patients with congestive heart failure without TR, this intermediate state of RV muscular hypertrophy was not present. Conclusion: The multiple causes of TR examined in this study changed RV shape in similar ways. Logistic regression classification based on these shape changes reliably identified patients with TR regardless of etiology. Furthermore, pulmonary hypertension without TR had unique shape features, described here as the "well compensated" RV. These results suggest shape modeling as a promising tool for defining severity of RV disease and risk of decompensation, particularly in patients with pulmonary hypertension.

Saturation recovery-prepared magnetic resonance angiography for assessment of left atrial and esophageal anatomy.

OBJECTIVES: Magnetic resonance angiography (MRA) has been established as an important imaging method in cardiac ablation procedures. In pulmonary vein (PV) isolation procedures, MRA has the potential to minimize the risk of severe complications, such as atrio-esophageal fistula, by providing detailed information on esophageal position relatively to cardiac structures. However, traditional non-gated, first-pass (FP) MRA approaches have several limitations, such as long breath-holds, non-uniform signal intensity throughout the left atrium (LA), and poor esophageal visualization. The aim of this observational study was to validate a respiratory-navigated, ECG-gated (EC), saturation recovery-prepared MRA technique for simultaneous imaging of LA, LA appendage, PVs, esophagus, and adjacent anatomical structures. METHODS: Before PVI, 106 consecutive patients with a history of AF underwent either conventional FP-MRA (n = 53 patients) or our new EC-MRA (n = 53 patients). Five quality scores (QS) of LA and esophagus visibility were assessed by two experienced readers. The non-parametric Mann-Whitney U-test was used to compare QS between FP-MRA and EC-MRA groups, and linear regression was applied to assess clinical contributors to image quality. RESULTS: EC-MRA demonstrated significantly better image quality than FP-MRA in every quality category. Esophageal visibility using the new MRA technique was markedly better than with the conventional FP-MRA technique (median 3.5 [IQR 1] vs median 1.0, p < 0.001). In contrast to FP-MRA, overall image quality of EC-MRA was not influenced by heart rate. CONCLUSION: Our ECG-gated, respiratory-navigated, saturation recovery-prepared MRA technique provides significantly better image quality and esophageal visibility than the established non-gated, breath-holding FP-MRA. Image quality of EC-MRA technique has the additional advantage of being unaffected by heart rate. ADVANCES IN KNOWLEDGE: Detailed information of cardiac anatomy has the potential to minimize the risk of severe complications and improve success rates in invasive electrophysiological studies. Our novel ECG-gated, respiratory-navigated, saturation recovery-prepared MRA technique provides significantly better image quality of LA and esophageal structures than the traditional first-pass algorithm. This new MRA technique is robust to arrhythmia (tachycardic, irregular heart rates) frequently observed in AF patients.

The association between transthoracic echocardiogram parameters and white matter hyperintensities.

OBJECTIVE: Identify abnormal cardiac chamber size and hemodynamic parameters on transthoracic echocardiogram (TTE) as predictors of advancing cerebral small vessel disease (CSVD) on brain magnetic resonance imaging (MRI). MATERIALS AND METHODS: A retrospective chart review of adults with a brain MRI and a 2-dimensional TTE was performed. WMH measured by the Fazekas score served as the primary outcome. We fit multivariate ordinal logistic regression models to the Fazekas score with the individual predictors of the TTE measurements and adjusted for potential confounders. RESULTS: 132 individuals were included. Cardiac functional markers were not significant, including tricuspid annular plane systolic excursion (p = 0.818), right ventricular ejection fraction (p = 0.818) and left ventricular ejection fraction (p = 0.673). Cardiac structural markers included right atrial area (p = 0.247), right ventricular internal diameter (RVID, p = 0.020) and left atrial area (LAA, p = 0.041). RVID and LAA were identified as being predictors, although the direction of the association suggested that normal values resulted in more WMH. Analysis of isolated DWM or PVWM Fazekas scores were not associated with cardiac structure or function. CONCLUSIONS: In our study, we found that normal LAA and RVID values were associated with an increased degree of WMH on MRI. This finding may represent earlier identification of WMH prior to TTE cardiac changes. Future studies are needed for more robust quantitative comparison as well as evaluation prospectively of the association between cardiac chamber sizes and development of WMH.

Quadricuspid Aortic Valve Stenosis: Expanding Our Experience in Transcatheter Aortic Valve Implantation.

To our knowledge, this is the first documented case of successful TAVI for severe quadricuspid aortic valve (QAV) stenosis performed in the U.S. and the first documented Sapien 3 valve implantation in a severely stenotic QAV.

Training the next generation of invasive cardiologists: Feasibility of implementing a trans-radial access program at an academic hospital.

BACKGROUND: Slow adoption of trans-radial access (TRA) for left heart catheterization (LHC) in the U.S. may be related to concerns about procedural complexity and a steep learning curve. However, TRA acceptance among novice operators remains poorly characterized. METHODS: We initiated a 1-year TRA learning period among lower-risk outpatients, followed by a "radial-first" policy for all LHC patients beginning year 2. By year 3, all fellows prospectively collected diagnostic LHC data as part of a quality improvement study. TRA procedural characteristics were compared with patients undergoing trans-femoral access for the 3months prior to the TRA program, and trends over time were evaluated. RESULTS: Between 7/2009 and 6/2012, we identified 960 patients undergoing LHC via TRA by 23 rotating cardiology fellows supervised by 5 interventional cardiologists. When evaluated against the 160 trans-femoral comparator patients, TRA patients had lower procedural success through the initial access site (88% vs. 99%, p<0.001) and longer fluoroscopy times (9.5 [5.8-15.9] vs. 6.5 [3.1-12.7] min, p<0.001), with similar contrast volumes and fewer catheters used. Despite tackling more complex patients during years 2-3, there were improvements in fluoroscopy times, catheter utilization, contrast volumes, and procedural success rates over time (all p<0.001). CONCLUSIONS: The dedicated adoption of TRA by an academic catheterization laboratory demonstrated improvements in efficiency and resource utilization over a relatively short period of time. Additional exposure to TRA during training may help facilitate acceptance of this approach among the next generation of invasive cardiologists. SHORT SUMMARY (FOR ANNOTATED TABLE OF CONTENTS): When initiating a trans-radial access program for cardiac catheterization at an academic training hospital, procedural success rates were lower and fluoroscopy times were higher than traditional trans-femoral access. Nonetheless, other procedural variables were similar between the 2 approaches, and improvements over time were consistent with the learning curves reported among experienced cardiologists in prior studies. Exposure to trans-radial access during training may help facilitate acceptance of this approach among the next generation of invasive cardiologists.

Transient cardiogenic shock during a crisis of pheochromocytoma triggered by high-dose exogenous corticosteroids.

We report a case of a 39-year-old woman who presented to the emergency department (ED) with symptoms of pharyngitis and fever. Diagnosed with streptococcal pharyngitis, she received antibiotics and dexamethasone, and was discharged. Within 24 h she returned to the ED with signs and symptoms of an acute coronary syndrome; she was thus given ß-blockers. Her coronary angiogram was normal. She developed cardiogenic shock with an ejection fraction (EF) of 10% and apical ballooning on echocardiography. Her condition improved with optimal medical therapy. Subsequent testing weeks later confirmed the presence of a pheochromocytoma. Following prazosin and an adrenalectomy, all her antihypertensive medications were weaned and her EF normalised. We believe the high-dose exogenous corticosteroids triggered a pheochromocytoma crisis. The concomitant use of ß-blockers without preceding α blockade resulted in cardiovascular collapse. Pheochromocytoma crisis must be included in the differential diagnosis of any dramatic haemodynamic collapse after administration of exogenous corticosteroid or ß-blockers.

Characteristics and survival of head and neck cancer by HPV status: a cancer registry-based study.

Elucidation of the role of human papillomavirus (HPV) in the etiology and prognosis of squamous carcinomas of the head and neck (HNSCC) is essential to optimize prevention and treatment strategies for this disease. We analyzed 385 HNSCC tissue blocks identified through a population-based cancer registry in Metropolitan Detroit for HPV DNA using a broad-spectrum PCR technique (SPF10-LiPA25) to correlate with patient and tumor characteristics and overall survival. Overall, HPV DNA (any type) was detected in 29.4% of all HNSCC, but it was significantly more prevalent (50.6%) in oropharyngeal sites (N=81), where 90% of HPV were type 16, than in other sites. HPV prevalence (any type) in oropharyngeal sites was highest in patients with a negative smoking indicator, Caucasians and in regional tumor stage. Likewise, only in oropharyngeal sites did patients overall positive to HPV show significantly better survival compared with HPV-negative patients, notably among those who had been irradiated. The best and the worst survival from cancer in oropharyngeal sites were found, respectively, among HPV-positive patients with negative smoking indicator and among HPV-negative patients with positive smoking indicator. The results of this study revealed that the presence of HPV DNA was associated with patients' specific characteristics and better overall survival exclusively in oropharyngeal sites. To define the fraction of HNSCC preventable by HPV vaccination or amenable to less aggressive treatment, however, tobacco exposure and HPV markers other than DNA presence need to be taken into account.