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Männer J. The Functional Significance of Cardiac Looping: Comparative Embryology, Anatomy, and Physiology of the Looped Design of Vertebrate Hearts. J Cardiovasc Dev Dis 2024; 11:252. [PMID: 39195160 DOI: 10.3390/jcdd11080252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 08/12/2024] [Accepted: 08/15/2024] [Indexed: 08/29/2024] Open
Abstract
The flow path of vertebrate hearts has a looped configuration characterized by curved (sigmoid) and twisted (chiral) components. The looped heart design is phylogenetically conserved among vertebrates and is thought to represent a significant determinant of cardiac pumping function. It evolves during the embryonic period of development by a process called "cardiac looping". During the past decades, remarkable progress has been made in the uncovering of genetic, molecular, and biophysical factors contributing to cardiac looping. Our present knowledge of the functional consequences of cardiac looping lags behind this impressive progress. This article provides an overview and discussion of the currently available information on looped heart design and its implications for the pumping function. It is emphasized that: (1) looping seems to improve the pumping efficiency of the valveless embryonic heart. (2) bilaterally asymmetric (chiral) looping plays a central role in determining the alignment and separation of the pulmonary and systemic flow paths in the multi-chambered heart of tetrapods. (3) chiral looping is not needed for efficient pumping of the two-chambered hearts of fish. (4) it is the sigmoid curving of the flow path that may improve the pumping efficiency of lower as well as higher vertebrate hearts.
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Affiliation(s)
- Jörg Männer
- Group Cardio-Embryology, Institute of Anatomy and Cell Biology, UMG, Georg-August-University Goettingen, D-37075 Goettingen, Germany
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Sherrid MV. On the Cause of Systolic Anterior Motion in Obstructive Hypertrophic Cardiomyopathy. J Am Soc Echocardiogr 2024; 37:782-786. [PMID: 38761985 DOI: 10.1016/j.echo.2024.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/04/2024] [Accepted: 05/06/2024] [Indexed: 05/20/2024]
Affiliation(s)
- Mark V Sherrid
- Hypertrophic Cardiomyopathy Program and Echocardiography Laboratory, Leon Charney Division of Cardiology, NYU Langone Health and New York University Grossman School of Medicine, New York, New York.
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Singh A, Razzouk L, Massera D, Sherrid MV. Acute Left Ventricular Ballooning: Tools to Differentiate Hypertrophic Cardiomyopathy with Outflow Obstruction from Neurohumoral Takotsubo Syndrome. Rev Cardiovasc Med 2023; 24:154. [PMID: 39076741 PMCID: PMC11273027 DOI: 10.31083/j.rcm2405154] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/13/2023] [Accepted: 03/27/2023] [Indexed: 07/31/2024] Open
Abstract
Despite considerable interest in the syndrome of acute left ventricular (LV) ballooning, its pathophysiology has remained ill-defined. In this review, we explore observational data describing two etiologies of acute LV ballooning: neurohumoral classic Takotsubo Syndrome (TTS), and acute severe unrelenting left ventricular outflow tract (LVOT) obstruction in patients with obstructive hypertrophic cardiomyopathy (HCM). We describe the clinical presentation and varying pathophysiology of these presentations, explore how echocardiography and cardiac catheterization may help differentiate between the two etiologies, and detail differences in management. We highlight the significant overlap as well as key differentiating features of these conditions, with the aim to improve diagnostic awareness and accuracy and appropriately tailor therapy.
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Affiliation(s)
- Arushi Singh
- Hypertrophic Cardiomyopathy Program, Leon H. Charney Division of Cardiology, Department of Medicine, New York University Langone Health, New York, NY 10016, USA
| | - Louai Razzouk
- Interventional Cardiology, Leon H. Charney Division of Cardiology, Department of Medicine, New York University Langone Health, New York, NY 10016, USA
| | - Daniele Massera
- Hypertrophic Cardiomyopathy Program, Leon H. Charney Division of Cardiology, Department of Medicine, New York University Langone Health, New York, NY 10016, USA
| | - Mark V. Sherrid
- Hypertrophic Cardiomyopathy Program, Leon H. Charney Division of Cardiology, Department of Medicine, New York University Langone Health, New York, NY 10016, USA
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Brown W, Wesalo J, Tsang M, Deiters A. Engineering Small Molecule Switches of Protein Function in Zebrafish Embryos. J Am Chem Soc 2023; 145:2395-2403. [PMID: 36662675 DOI: 10.1021/jacs.2c11366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Precise temporally regulated protein function directs the highly complex processes that make up embryo development. The zebrafish embryo is an excellent model organism to study development, and conditional control over enzymatic activity is desirable to target chemical intervention to specific developmental events and to investigate biological mechanisms. Surprisingly few, generally applicable small molecule switches of protein function exist in zebrafish. Genetic code expansion allows for site-specific incorporation of unnatural amino acids into proteins that contain caging groups that are removed through addition of small molecule triggers such as phosphines or tetrazines. This broadly applicable control of protein function was applied to activate several enzymes, including a GTPase and a protease, with temporal precision in zebrafish embryos. Simple addition of the small molecule to the media produces robust and tunable protein activation, which was used to gain insight into the development of a congenital heart defect from a RASopathy mutant of NRAS and to control DNA and protein cleavage events catalyzed by a viral recombinase and a viral protease, respectively.
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Affiliation(s)
- Wes Brown
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Joshua Wesalo
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Michael Tsang
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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Systolic Anterior Motion of the Mitral Valve in the Presence of Annular Calcification. J Am Soc Echocardiogr 2022; 36:421-427. [PMID: 36529336 DOI: 10.1016/j.echo.2022.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 11/19/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND Mitral annular calcification (MAC) has been reported as a possible cause of systolic anterior motion (SAM) of the mitral valve and dynamic left ventricular outflow tract (LVOT) obstruction. While morphologic features predisposing to SAM in other clinical settings have been described, patients with MAC+SAM have not been systematically investigated. We hypothesized that bulky calcium deposits in the mitral annulus could displace the valve toward the septum, thus promoting development of SAM. METHODS We studied 30 patients with severe MAC who had SAM with septal contact. Three comparator groups (matched for age and sex) were developed: 30 controls without MAC or SAM, 30 with severe MAC but no SAM, and 30 with SAM but no MAC. RESULTS Significant differences were found across groups for mitral valve coaptation point-septal distance (CSD), anterior mitral leaflet (AML) length, left ventricular diastolic dimension, and ejection fraction. Comparing all MAC subjects (n = 60) with controls, CSD was less (20.5 ± 4.1 vs 23.2 ± 3.7 mm, P = .003) and ejection fraction was higher (67.7% ± 7.8% vs 60.9% ± 6.4%, P < .0001) in MAC patients. Within MAC subjects AML was longer (21.9 ± 3.0 vs 17.4 ± 2.2 mm, P < .0001) and CSD was smaller (18.0 ± 2.7 vs 23.1 ± 3.6 mm, P < .0001) when SAM was present despite similar height of the calcium bar in the 2 MAC groups (12.4 ± 2.9 vs 11.1 ± 3.1 mm, P = .11). Regression analysis confirmed AML length and CSD as independent predictors of SAM. MAC+SAM patients also had more echocardiographic risk factors for SAM (acute aortomitral angle, small LVOT, long AML, small CSD, and presence of a septal bump) than MAC/no-SAM patients (3.4 ± 0.9 vs 1.8 ± 1.0, P < .0001). CONCLUSIONS Bulky MAC appears to contribute to dynamic LVOT obstruction when it accumulates in such a way that the mitral valve is displaced anteriorly toward the septum. However, other features are also associated with SAM in these patients, particularly a long AML. A combination of morphologic features and favorable hemodynamics may be needed for SAM to develop in patients with severe MAC.
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Usui A, Mutsuga M. Surgical Management for Systolic Anterior Motion (SAM) of the Mitral Valve in Obstructive Hypertrophic Myopathy. Ann Thorac Cardiovasc Surg 2022; 28:239-248. [PMID: 35851569 PMCID: PMC9433892 DOI: 10.5761/atcs.ra.22-00103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In patients with obstructive hypertrophic cardiomyopathy, left ventricular outflow tract (LVOT) obstruction can be created by the hypertrophic interventricular septum (IVS) as well as systolic anterior motion (SAM) of the anterior mitral leaflet (AML). Sufficient septal myectomy is a fundamental surgical technique to treat LVOT obstruction, however, direct surgical management for SAM is another key aspect. Besides the hypertrophic IVS, mitral valve, subvalvular apparatus, and papillary muscle may play important role for SAM and several surgical techniques have been proposed to treat SAM in literature. In this review, each surgical technique is classified by the anatomical structure on which the surgical procedure is applied. The AML is the main surgical site and is applied with plication (vertical plication, resection–plication–release strategy), extension (the AML extension, transverse incision of the AML), sutured (edge-to-edge repair, anterior leaflet retention plasty), or traction (floating stitch, papillary muscle-to-anterior annulus stitches, paradoxical stitches, transposition of a directed chorda tendinea to the AML). Height reduction of the posterior mitral valve leaflet and papillary muscle reorientation are other techniques. We should understand theoretical aspects of each technique on correction of anatomical and functional abnormalities of the structure and should apply them under proper indication.
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Affiliation(s)
- Akihiko Usui
- Department of Cardiovascular Surgery, Fujita Health University Okazaki Medical Center, Okazaki, Aichi, Japan
| | - Masato Mutsuga
- Department of Cardiac Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
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Surgery for Hypertrophic Obstructive Cardiomyopathy: Comprehensive LVOT Management beyond Septal Myectomy. J Clin Med 2021; 10:jcm10194397. [PMID: 34640415 PMCID: PMC8509570 DOI: 10.3390/jcm10194397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/19/2021] [Accepted: 09/24/2021] [Indexed: 11/28/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a complex, underestimated, multifaceted disease frequently associated with left ventricular outflow tract (LVOT) obstruction. It is clearly demonstrated that this is due not only to septal hypertrophy but also to systolic anterior motion (SAM) of mitral valve leaflets secondary to mitral valve/subvalvular apparatus abnormalities. Surgical treatment involves performing an extended septal myectomy, eventually followed by ancillary procedures to those structures responsible for maintaining LVOT obstruction, if necessary. In this review, we describe the spectrum of possible surgical techniques beyond septal myectomy and their pathophysiologic rationale.
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Sun Y, Yang F, Liu Y, Yu M, Wu F, Wang G. Di-2-ethylhexyl phthalate induces heart looping disorders during zebrafish development. Toxicol Ind Health 2021; 37:391-397. [PMID: 34047658 DOI: 10.1177/07482337211019184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Di-2-ethylhexyl phthalate (DEHP) is a type of plasticizer widely used in industry. It is well-known for its toxic effects to endocrine and reproductive systems and has been detected in amniotic fluid and placenta. In the present study, we explored the effects of DEHP on heart development by using zebrafish as a model organism. DEHP (0.02 pg) was injected into the yolk sac of zebrafish embryos at the one-cell stage. No significant difference was found in embryonic lethality between control and DEHP groups at 1-day postfertilization (dpf), but mortality significantly increased in DEHP groups at 2 and 3 dpf. The average heart rate was significantly reduced in the surviving DEHP-treated zebrafish larvae at 3 and 4 dpf. In addition, massive pericardial edema was found in DEHP-treated zebrafish (12.6 ± 1.5%), which was significantly higher than that of the control group. Serious heart looping disorder was also observed in DEHP-treated larvae, mainly manifested with an elongated atrial-ventricular distance. Moreover, the expression of heart development transcription factors was affected by DEHP injection. Real-time polymerase chain reaction confirmed that five transcription factors (hand2, tp53, mef2c, esr1, and tbx18) were significantly downregulated in the DEHP group at 2 dpf, and three transcription factors (zic3, tcf21, and gata4) were significantly upregulated. Our results emphasize the need for the development of a nontoxic plasticizer to prevent possible deleterious effects on humans and other life-forms.
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Affiliation(s)
- Yangyong Sun
- Department of Cardiovascular Surgery, Institute of Cardiac Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Fan Yang
- Department of Cardiovascular Surgery, Institute of Cardiac Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Yang Liu
- Department of Cardiovascular Surgery, Institute of Cardiac Surgery, Changhai Hospital, Naval Medical University, Shanghai, China.,Department of Critical Care Medicine, Naval Medical Center of PLA, Shanghai, China
| | - Manli Yu
- Department of Cardiology, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Feng Wu
- Department of Cardiology, Changhai Hospital, Naval Medical University, Shanghai, China.,Department of Cardiology, the 72th Group Army Hospital of PLA, Zhejiang, China
| | - Guokun Wang
- Department of Cardiovascular Surgery, Institute of Cardiac Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
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Affiliation(s)
- Mark V. Sherrid
- Hypertrophic Cardiomyopathy ProgramDivision of CardiologyDepartment of MedicineNYU Grossman School of MedicineNYU Langone HealthNew YorkNY
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Sherrid MV, Männer J, Swistel DG, Olivotto I, Halpern DG. On the Cardiac Loop and Its Failing: Left Ventricular Outflow Tract Obstruction. J Am Heart Assoc 2020; 9:e014857. [PMID: 31986992 PMCID: PMC7033877 DOI: 10.1161/jaha.119.014857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/20/2019] [Indexed: 01/14/2023]
Affiliation(s)
- Mark V. Sherrid
- Hypertrophic CardiomyopathyNew York University School of MedicineNew YorkNY
| | - Jörg Männer
- Department of Anatomy and EmbryologyGeorg‐August University of GöttingenGöttingenGermany
| | - Daniel G. Swistel
- Department of Cardiothoracic SurgeryNew York University School of MedicineNew YorkNY
| | | | - Dan G. Halpern
- Adult Congenital Heart Disease ProgramNew York University School of MedicineNew YorkNY
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