Heart Shaped Left Ventricle: A Diagnosis of Double-Chambered Left Ventricle by Multimodality Imaging
2021; Lippincott Williams & Wilkins; Volume: 14; Issue: 7 Linguagem: Inglês
10.1161/circimaging.120.012185
ISSN1942-0080
AutoresCorina Iorgoveanu, Ahmed Zaghloul, Sidakpal Panaich, Kimberly Delcour,
Tópico(s)Coronary Artery Anomalies
ResumoHomeCirculation: Cardiovascular ImagingVol. 14, No. 7Heart Shaped Left Ventricle: A Diagnosis of Double-Chambered Left Ventricle by Multimodality Imaging Free AccessCase ReportPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyRedditDiggEmail Jump toFree AccessCase ReportPDF/EPUBHeart Shaped Left Ventricle: A Diagnosis of Double-Chambered Left Ventricle by Multimodality Imaging Corina Iorgoveanu, MD, Ahmed Zaghloul, MD, Sidakpal Panaich, MD and Kimberly Delcour, MD Corina IorgoveanuCorina Iorgoveanu Correspondence to: Corina Iorgoveanu, MD, Iowa ACC Women in Cardiology Fellow in Training Chair, Division of Cardiology, Department of Internal Medicine, University of Iowa Hospitals and Clinics, University of Iowa Health Care, 200 Hawkins Dr, Iowa City, IA 52242. Email E-mail Address: [email protected] https://orcid.org/0000-0001-7901-4955 Division of Cardiovascular Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA. , Ahmed ZaghloulAhmed Zaghloul Division of Cardiovascular Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA. , Sidakpal PanaichSidakpal Panaich https://orcid.org/0000-0003-1643-4236 Division of Cardiovascular Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA. and Kimberly DelcourKimberly Delcour Division of Cardiovascular Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA. Originally published22 Jun 2021https://doi.org/10.1161/CIRCIMAGING.120.012185Circulation: Cardiovascular Imaging. 2021;14Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: June 22, 2021: Ahead of Print Double chamber left ventricle (DCLV), also known as bifid cardiac apex, is a rare developmental anomaly of human heart, in which the left ventricle (LV) chamber is divided into 2 by an abnormal muscle or septum. The clinical significance of this anomaly has thus far remained ambiguous. We report the case of a 75-year-old female with a history of bioprosthetic mitral valve replacement because of severe primary mitral regurgitation about 10 years before she was referred to our center for evaluation of new-onset progressive dyspnea on exertion of 6 months duration. Her other past medical history also included decreased ejection fraction for which she underwent cardiac resynchronization therapy, subsequent recovered ejection fraction, and paroxysmal atrial fibrillation on anticoagulation. At presentation, she had dyspnea on exertion (New York Heart Association function class III) and fatigue. On physical examination, jugular venous pressure was moderately elevated, both heart sounds (S1 and S2) were normal, there was a soft apical holosystolic murmur with radiation to the axilla. Electrocardiography showed an atrial-sensed ventricular-paced rhythm with a heart rate of 65 beat/minute (Figure 1). Transthoracic 2-dimensional and contrast echocardiography (Figure 2) revealed a mildly decreased LV systolic function (left ventricular ejection fraction=40%–45%), as well as a thick-walled muscular ridge extending from the apex up to the base of LV, dividing the LV into 2 distinct contracting chambers, highly suspicious of a dual chamber left ventricle (Figures 2 and 3). The mitral valve was overriding both LV chambers. Doppler echocardiography revealed no signs of ejection nor filling obstruction. These findings were confirmed by transesophageal echocardiography, which was performed mainly for assessment of mitral valve (Figure 4). Coronary angiography indicated a normal coronary artery anatomy. Computed tomography heart confirmed the presence of a thick-walled muscular accessory septum arising from the apex (Figure 5). Patient eventually underwent transcatheter mitral valve-in-valve without complications.Download figureDownload PowerPointFigure 1. The twelve-lead ECG shows a normal sinus rhythm at a rate of 65 bpm with ventricular paced complexes suggestive of bi-ventricular device.Download figureDownload PowerPointFigure 2. Two-dimensional transthoracic echocardiogram image. Apical 2-chamber view, revealing the 2 left ventricular chambers separated by an abnormally located muscle bundle in the left ventricular apical portion.Download figureDownload PowerPointFigure 3. Apical 4-chamber view. A thick-walled accessory septum arising from the apex of left ventricle, going parallel to the inter ventricular septum. It divides the left ventricle into 2 distinct chambers, both connected by a common outflow segment thereby giving it a heart-shaped appearance.Download figureDownload PowerPointFigure 4. Transesophageal echocardiogram 4-chamber view. Note the thick-walled septum dividing the left ventricular cavity.Download figureDownload PowerPointFigure 5. Multiplanar reformat computed tomography angiography images depicting the accessory septum that divides the left ventricle into 2 distinct chambers.Double chamber left ventricle describes the subdivision of the LV cavity by an accessory septum into 2 distinct chambers. The right and left ventricles develop independently on either side of the primitive plate before they eventually merge. During the fifth to eighth week of embryonic growth, a prominent cardiac notch is noticeable on the external surface of the heart, indicating the area of the developing inter-ventricular septum and usually disappears by the eleventh week of gestation. Its postnatal presence is likely the precursor to a bifid cardiac apex.1 This cardiac anomaly was described in 1912 by Dr Franklin Mall as a bulbo-spiral band. In contrast to human anatomy, the division of the left ventricle is a common finding in several marine mammals, and in the dugong the cleft reaches almost the base of the ventricle. Dr Mall, while studying the development of the heart in 100 hearts in serial sections and 20 entire embryo hearts dissected under the microscope, he found that in embryos up to 10 mm in length, the heart is still in amphibian form, but it takes on the adult mammalian form shortly after. This study found 8 specimens over 11 mm long with divided apex, emphasizing the tendency for the divided apex to disappear later on during organogenesis.2 When present, this is usually associated with other congenital heart anomalies.1 The etiology of double chamber left ventricle is poorly understood. A study by Leung et al analyzed the role of Rac1 in the development of defects in cardiac septation. The results suggest that Rac1 deficiency impairs elongation and cytoskeleton organization of cardiomyocytes, resulting in bifid cardiac apex.3 Double chamber left ventricle must be differentiated from congenital left ventricular diverticulum, aneurysms and cysts. Distinguishing between these etiologies is challenging but mandatory, given the implications associated with these conditions. Double chamber left ventricle contains all 3 cardiac layers, similar to a left ventricular diverticulum, but has a wide communication with the LV chamber, similar to an aneurysm.4 Most cases of double chamber left ventricle are congenital, secondary to abnormal development of the myocardial intratrabecular sinusoids. This anomaly has been previously described in association with endocardial fibroelastosis or hypertrophic cardiomyopathy.4 Echocardiography, although the first modality used in evaluation of double chamber left ventricle, is usually followed by a different imaging modality to support the diagnosis. Computed tomography can aid in the detection of this condition, as outlined in our case. Cardiac MRI, because of its good spatial and temporal resolutions, multiplanar imaging capabilities, and its ability for tissue characterization, provides a better delineation of this condition. A definite diagnosis is challenging without microscopic examination.4 Because of its rarity, no definite data on the treatments, prognosis, outcomes, and its potential complications are available. Multimodality imaging plays a crucial part in making the correct diagnosis and management decision, especially when tissue biopsy is not always available. Clinicians should be aware and able to distinguish between this condition and its mimics. Finally, with our case, we point out the presence of a bifid cardiac apex in the absence of any significant congenital cardiac anomalies.Sources of FundingNone.Disclosures None.FootnotesFor Sources of Funding and Disclosures, see page 666.Correspondence to: Corina Iorgoveanu, MD, Iowa ACC Women in Cardiology Fellow in Training Chair, Division of Cardiology, Department of Internal Medicine, University of Iowa Hospitals and Clinics, University of Iowa Health Care, 200 Hawkins Dr, Iowa City, IA 52242. Email corina.[email protected]comReferences1. De Bartolo D, De Luca E, Arena V, Ausania F, Buja LM, Ricci P. Bifid cardiac apex and high take off: an unusual association in a case of sudden death.Cardiovasc Pathol. 2016; 25:512–514. doi: 10.1016/j.carpath.2016.09.001CrossrefMedlineGoogle Scholar2. Mall FP. Bifid apex of the human heart. Anat. Rec. 1912; 6;167. doi:10.1002/ar.1090060402CrossrefGoogle Scholar3. Leung C, Lu X, Liu M, Feng Q. Rac1 signaling is critical to cardiomyocyte polarity and embryonic heart development.J Am Heart Assoc. 2014; 3:e001271. doi: 10.1161/JAHA.114.001271LinkGoogle Scholar4. Rajiah P, Thomas J, Smedira N, Desai MY. Double-chambered left ventricle due to fibroelastotic membrane: an unusual case.J Thorac Imaging. 2012; 27:W5–W7. doi: 10.1097/RTI.0b013e3181fef181CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails July 2021Vol 14, Issue 7Article InformationMetrics © 2021 American Heart Association, Inc.https://doi.org/10.1161/CIRCIMAGING.120.012185PMID: 34154393 Originally publishedJune 22, 2021 Keywordsatrial fibrillationechocardiographydyspneafatigueheart ratePDF download Advertisement SubjectsComputerized Tomography (CT)Diagnostic TestingImaging
Referência(s)