A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one common ventricle. The ventricular septum consists of an inferior muscular and superior membranous portion and is extensively innervated with conducting cardiomyocytes.
The membranous portion, which is close to the atrioventricular node, is most commonly affected in adults and older children in the United States.[1] It is also the type that will most commonly require surgical intervention, comprising over 80% of cases.[2]
Membranous ventricular septal defects are more common than muscular ventricular septal defects, and are the most common congenital cardiac anomaly.[3]
Ventricular septal defect is usually symptomless at birth. It usually manifests a few weeks after birth.
VSD is an acyanotic congenital heart defect, aka a left-to-right shunt, so there are no signs of cyanosis in the early stage. However, uncorrected VSD can increase pulmonary resistance leading to the reversal of the shunt and corresponding cyanosis.
The restrictive VSDs (smaller defects) are associated with a louder murmur and more palpable thrill (grade IV murmur). Larger defects may eventually be associated with pulmonary hypertension due to the increased blood flow. Over time this may lead to an Eisenmenger's syndrome the original VSD operating with a left-to-right shunt, now becomes a right-to-left shunt because of the increased pressures in the pulmonary vascular bed.
Congenital VSDs are frequently associated with other congenital conditions, such as Down syndrome.[5]
A VSD can also form a few days after a myocardial infarction[6] (heart attack) due to mechanical tearing of the septal wall, before scar tissue forms, when macrophages start remodeling the dead heart tissue.
The causes of congenital VSD (ventricular septal defect) include the incomplete looping of the heart during days 24-28 of development. Faults with NKX2.5 gene are usually associated with isolated (non syndromic) ASD in humans when one copy is missing.
During ventricular contraction, or systole, some of the blood from the left ventricle leaks into the right ventricle, passes through the lungs and reenters the left ventricle via the pulmonary veins and left atrium. This has two net effects. First, the circuitous refluxing of blood causes volume overload on the left ventricle. Second, because the left ventricle normally has a much higher systolic pressure (~120mmHg) than the right ventricle (~20mmHg), the leakage of blood into the right ventricle therefore elevates right ventricular pressure and volume, causing pulmonary hypertension with its associated symptoms.
In serious cases, the pulmonary arterial pressure can reach levels that equal the systemic pressure. This reverses the left to right shunt, so that blood then flows from the right ventricle into the left ventricle, resulting in cyanosis, as blood is by-passing the lungs for oxygenation.[7]
This effect is more noticeable in patients with larger defects, who may present with breathlessness, poor feeding and failure to thrive in infancy. Patients with smaller defects may be asymptomatic. Four different septal defects exist, with perimembranous most common, outlet, atrioventricular, and muscular less commonly.[8]
A VSD can be detected by cardiac auscultation. Classically, a VSD causes a pathognomonic holo- or pansystolic murmur. Auscultation is generally considered sufficient for detecting a significant VSD. The murmur depends on the abnormal flow of blood from the left ventricle, through the VSD, to the right ventricle. If there is not much difference in pressure between the left and right ventricles, then the flow of blood through the VSD will not be very great and the VSD may be silent. This situation occurs a) in the fetus (when the right and left ventricular pressures are essentially equal), b) for a short time after birth (before the right ventricular pressure has decreased), and c) as a late complication of unrepaired VSD. Confirmation of cardiac auscultation can be obtained by non-invasive cardiac ultrasound (echocardiography). To more accurately measure ventricular pressures, cardiac catheterization, can be performed.
Although there are several classifications for VSD, the most accepted and unified classification is that of Congenital Heart Surgery Nomenclature and Database Project.[9] The classification is based on the location of the VSD on the right ventricular surface of the inter ventricular septum and is as follows:
Type 1 is sub aortic
Type 3 also known as inlet (or AV canal type).
Type 4 also known as muscular (trabecular)
Type: Gerbode also known as left ventricular to right atrial communication
Heart anatomic view of right ventricle and right atrium with example ventricular septal defects
Ventricular septal defect
Figure A shows the structure and blood flow in the interior of a normal heart. Figure B shows two common locations for a ventricular septal defect. The defect allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle.
Most cases do not need treatment and heal at the first years of life. Treatment is either conservative or surgical. Smaller congenital VSDs often close on their own, as the heart grows, and in such cases may be treated conservatively. Some cases may necessitate surgical intervention, i.e. with the following indications:
1. Failure of congestive cardiac failure to respond to medications
2. VSD with pulmonic stenosis
3. Large VSD with pulmonary hypertension
4. VSD with aortic regurgitation
For the surgical procedure, a heart-lung machine is required and a median sternotomy is performed. Percutaneous endovascular procedures are less invasive and can be done on a beating heart, but are only suitable for certain patients. Repair of most VSDs is complicated by the fact that the conducting system of the heart is in the immediate vicinity.
Ventricular septum defect in infants is initially treated medically with cardiac glycosides (e.g., digoxin 10-20g/kg per day), loop diuretics (e.g., furosemide 13mg/kg per day) and ACE inhibitors (e.g., captopril 0.52mg/kg per day).
A device, known as the Amplatzer muscular VSD occluder, may be used to close certain VSDs.[10] It was initially approved in 2009.[10] It appears to work well and be safe.[10] The cost is also lower than having open heart surgery.[10] The device is placed through a small incision in the groin.[11]
The Amplatzer septal occluder was shown to have full closure of the ventricular defect within the 24 hours of placement.[12] It has a low risk of embolism after implantation.[13] Some tricuspid valve regurgitation was shown after the procedure that could possibly be due from the right ventricular disc.[12] There have been some reports that the Amplatzer septal occluder may cause life-threatening erosion of the tissue inside the heart.[14] This occurs in one percent of people implanted with the device and requires immediate open-heart surgery.[14] This erosion occurs due to improper sizing of the device resulting with it being too large for the defect, causing rubbing of the septal tissue and erosion.[14]
a) Surgical closure of a Perimembranous VSD is performed on cardiopulmonary bypass with ischemic arrest. Patients are usually cooled to 28 degrees. Percutaneous Device closure of these defects is rarely performed in the United States because of the reported incidence of both early and late onset complete heart block after device closure, presumably secondary to device trauma to the AV node.
b) Surgical exposure is achieved through the right atrium. The tricuspid valve septal leaflet is retracted or incised to expose the defect margins.
c) Several patch materials are available, including native pericardium, bovine pericardium, PTFE (Gore-Tex or Impra), or Dacron.
d) Suture techniques include horizontal pledgeted mattress sutures, and running polypropylene suture.
e) Critical attention is necessary to avoid injury to the conduction system located on the left ventricular side of the interventricular septum near the papillary muscle of the conus.
f) Care is taken to avoid injury to the aortic valve with sutures.
g) Once the repair is complete, the heart is extensively deaired by venting blood through the aortic cardioplegia site, and by infusing Carbon Dioxide into the operative field to displace air.
h) Intraoperative transesophageal echocardiography is used to confirm secure closure of the VSD, normal function of the aortic and tricuspid valves, good ventricular function, and the elimination of all air from the left side of the heart.
i) The sternum, fascia and skin are closed, with potential placement of a local anesthetic infusion catheter under the fascia, to enhance postoperative pain control.
j) Multiple muscular VSDs are a challenge to close, achieving a complete closure can be aided by the use of fluorescein dye.[15]
VSDs are the most common congenital cardiac abnormalities. They are found in 30-60% of all newborns with a congenital heart defect, or about 2-6 per 1000 births. During heart formation, when the heart begins life as a hollow tube, it begins to partition, forming septa. If this does not occur properly it can lead to an opening being left within the ventricular septum. It is debatable whether all those defects are true heart defects, or if some of them are normal phenomena, since most of the trabecular VSDs close spontaneously.[16] Prospective studies give a prevalence of 2-5 per 100 births of trabecular VSDs that close shortly after birth in 80-90% of the cases.[17][18]
More:
Ventricular septal defect - Wikipedia
- Managing Right Ventricular Failure in PAH: An Algorithmic Approach | Advances in ... - April 13th, 2018 [April 13th, 2018]
- What Is the Ejection Fraction? - Verywell Health - May 12th, 2018 [May 12th, 2018]
- Heart Failure Medication: Beta-Blockers, Alpha Activity ... - July 7th, 2018 [July 7th, 2018]
- Acute Management of Pulmonary Embolism - American College ... - July 17th, 2018 [July 17th, 2018]
- Ventricular Remodeling | Profiles RNS - July 24th, 2018 [July 24th, 2018]
- Left ventricular hypertrophy - Wikipedia - August 20th, 2018 [August 20th, 2018]
- Ventricular Remodeling Surgery (SVR) - September 24th, 2018 [September 24th, 2018]
- Left Ventricular Remodeling in Heart Failure | JACC ... - November 25th, 2018 [November 25th, 2018]
- Ventricular dysfunction in heart failure - Britannica.com - December 25th, 2018 [December 25th, 2018]
- TIMI Study Group - LEADERSHIP - January 31st, 2019 [January 31st, 2019]
- Ventricular Remodeling Procedure | Main Line Health ... - February 24th, 2019 [February 24th, 2019]
- BioLineRx Ltd. (BLRX)'s Financial Results Comparing With Coherus BioSciences Inc. (NASDAQ:CHRS) - Stocks Beat - September 18th, 2019 [September 18th, 2019]
- Reviewing Aeterna Zentaris Inc. (AEZS)'s and BioLineRx Ltd. (NASDAQ:BLRX)'s results - Stocks Beat - September 18th, 2019 [September 18th, 2019]
- Karuna Therapeutics Inc. (KRTX) and BioLineRx Ltd. (NASDAQ:BLRX) Comparing side by side - Stocks Beat - September 18th, 2019 [September 18th, 2019]
- Arbutus Biopharma Corporation (ABUS)'s Financial Results Comparing With BioLineRx Ltd. (NASDAQ:BLRX) - The EN Herald - September 18th, 2019 [September 18th, 2019]
- Cardiac Dimensions touts Carillon TMVR study - Mass Device - September 18th, 2019 [September 18th, 2019]
- New PROVE-HF Data May Reassure Clinicians of Sacubitril/Valsartan Benefit in HFrEF - TCTMD - September 18th, 2019 [September 18th, 2019]
- Cardiac Restoration Systems Market Will Make a Huge Impact in Near Future - Wolf Mirror - September 18th, 2019 [September 18th, 2019]
- Reduce Fmr Study Shows Cardiac Dimensions' Carillon System Significantly Improves Mitral Regurgitation And Slows Worsening Of Heart Failure - TCTMD - September 18th, 2019 [September 18th, 2019]
- Heart Failure Society of America 2019: Virtual Visits, Spironolactone Issues, and Reasons to Worry - DocWire News - September 18th, 2019 [September 18th, 2019]
- LV Reverse Remodeling Not Improved by SGLT-2 Inhibitor - DocWire News - September 18th, 2019 [September 18th, 2019]
- BioLineRx Ltd. (BLRX)'s Financial Results Comparing With Soligenix Inc. (NASDAQ:SNGX) - CryptoCoinsTribune - September 22nd, 2019 [September 22nd, 2019]
- Biolinerx LTD. American Depositary Shares (NASDAQ:BLRX) Could Burn Your Long Portfolio After More Shorts - The MAK Daily - September 22nd, 2019 [September 22nd, 2019]
- Reviewing BioLineRx Ltd. (BLRX)'s and Dicerna Pharmaceuticals Inc. (NASDAQ:DRNA)'s results - CryptoCoinsTribune - September 22nd, 2019 [September 22nd, 2019]
- Comparison of Protalix BioTherapeutics Inc. (PLX) and BioLineRx Ltd. (NASDAQ:BLRX) - MS Wkly - October 19th, 2019 [October 19th, 2019]
- Contrasting of BioLineRx Ltd. (BLRX) and Edge Therapeutics Inc. (:) - MS Wkly - October 19th, 2019 [October 19th, 2019]
- Contrasting of BioLineRx Ltd. (BLRX) and Protalix BioTherapeutics Inc. (NYSEAMERICAN:PLX) - The Broch Herald - November 7th, 2019 [November 7th, 2019]
- BioLineRx Ltd. (BLRX)'s Financial Results Comparing With Cyanotech Corporation (NASDAQ:CYAN) - The Broch Herald - November 7th, 2019 [November 7th, 2019]
- Triple-Gene Announces Completion of Enrollment and Dosing in Phase 1 Trial of INXN-4001, First Multigenic Investigational Therapeutic Candidate for... - November 7th, 2019 [November 7th, 2019]
- Contrasting of BioLineRx Ltd. (BLRX) and Moderna Inc. (NASDAQ:MRNA) - The Broch Herald - December 3rd, 2019 [December 3rd, 2019]
- Edited Transcript of MYOK earnings conference call or presentation 11-Nov-19 1:30pm GMT - Yahoo Finance - December 3rd, 2019 [December 3rd, 2019]
- Cardiac Restoration Systems Market: Key Growth Factors and Industry Analysis 2018 - 2028 - The Market Expedition - December 3rd, 2019 [December 3rd, 2019]
- Velocity Transfer Function In The Right Pulmonary Artery And Impaired | COPD - Dove Medical Press - December 3rd, 2019 [December 3rd, 2019]
- 3 Stocks to Buy Ahead of the Next Market Crash - The Motley Fool - December 3rd, 2019 [December 3rd, 2019]
- Pulmonary Hypertension, Common in TAVR Patients, Linked to Lower Survival - TCTMD - December 3rd, 2019 [December 3rd, 2019]
- Patients With Chemotherapy-Induced Cardiomyopathy Show Improvements in LVEF After Cardiac Resynchronization Therapy - AJMC.com Managed Markets Network - December 4th, 2019 [December 4th, 2019]
- BioVentrix Announces Publication of Positive One-Year Outcomes for Revivent TC System - Yahoo Finance - December 4th, 2019 [December 4th, 2019]
- Cardiac Restoration Systems Market Forecasted To Surpass The Value Of US$ XX Mn/Bn By 2055 2017 2025 - Weekly News Times - December 13th, 2019 [December 13th, 2019]
- The Outer Line: The impact of endurance training on the cardiac health of women - VeloNews - December 13th, 2019 [December 13th, 2019]
- Contrasting of Insmed Incorporated (INSM) and BioLineRx Ltd. (NASDAQ:BLRX) - The CoinGlobalist - December 16th, 2019 [December 16th, 2019]
- CARDIAC RESTORATION SYSTEMS MARKET ANALYSIS TRENDS, GROWTH OPPORTUNITIES, SIZE, TYPE, DYNAMIC DEMAND AND DRIVES WITH FORECASTS TO 2028 - Voice of... - January 13th, 2020 [January 13th, 2020]
- Early Expressed Circulating Long Noncoding RNA CHAST is Associated with Cardiac Contractile Function in Patients with Acute Myocardial Infarction -... - January 13th, 2020 [January 13th, 2020]
- Clinical Phenogroups in Heart Failure With Preserved Ejection Fraction: Detailed Phenotypes, Prognosis, and Response to Spironolactone - DocWire News - January 23rd, 2020 [January 23rd, 2020]
- Increased Long-Term Risk for Venous Thromboembolism After Heart Failure - The Cardiology Advisor - January 23rd, 2020 [January 23rd, 2020]
- Retinoid X receptor alpha is a spatiotemporally predominant therapeutic target for anthracycline-induced cardiotoxicity - Science Advances - February 1st, 2020 [February 1st, 2020]
- Coronary Microvascular Dysfunction Found to Increase Risk for CV Events in Chronic Kidney Disease - The Cardiology Advisor - February 1st, 2020 [February 1st, 2020]
- New Data Confirms Cardiac Dimensions' Carillon System Shows Favorable Long-Term Survival Rate In Patients With Functional Mitral Regurgitation -... - February 26th, 2020 [February 26th, 2020]
- BioVentrix Announces Ralph Stephan von Bardeleben, MD, as Co- Principal Investigator of the REVIVE-HF Clinical Trial - Yahoo Finance - March 5th, 2020 [March 5th, 2020]
- Relationship between histopathological features of aspirated thrombi and long-term left ventricular function in patients with ST-segment elevation... - March 15th, 2020 [March 15th, 2020]
- FierceMedTech Names BioVentrix as One of Its "Fierce 15" Companies of 2019 - Yahoo Finance - March 15th, 2020 [March 15th, 2020]
- Causes and Prevention of Ventricular Remodeling After MI ... - March 16th, 2020 [March 16th, 2020]
- Left Ventricular Remodelling - ECR Journal - April 23rd, 2020 [April 23rd, 2020]
- Cardiac Restoration Systems Market to Make Great Impact in Near Future by 2026 - The Canton Independent Sentinel - June 12th, 2020 [June 12th, 2020]
- Multi-Society Guidelines on the Use of Multimodality CV Imaging in Competitive Athletes - The Cardiology Advisor - June 12th, 2020 [June 12th, 2020]
- Chronic PDE5i Treatment Found to Improve Cardiac Remodeling in Men, but Not Women, With Diabetic Cardiomyopathy - Endocrinology Advisor - June 12th, 2020 [June 12th, 2020]
- Acceleron to Host Conference Call and Webcast to Review Results of PULSAR Phase 2 Trial of Sotatercept Presented at American Thoracic Society 2020... - June 23rd, 2020 [June 23rd, 2020]
- American Heart Association and Barth Syndrome Foundation Partner to Address Rare Disease - PR Web - August 29th, 2020 [August 29th, 2020]
- The Association of Cardio-Ankle Vascular Index (CAVI) with Biatrial Remodeling in Atrial Fibrillation - DocWire News - September 3rd, 2020 [September 3rd, 2020]
- Cardiac Dimensions Announces Australian Therapeutic Goods Administration's Approval of the Carillon System for the Treatment of Functional Mitral... - September 3rd, 2020 [September 3rd, 2020]
- Sep 4 2020 This Week in Cardiology - Medscape - September 5th, 2020 [September 5th, 2020]
- Emerging treatment helps reverse heart failure in some patients - Science Codex - October 27th, 2020 [October 27th, 2020]
- GMAX Biopharm gives first does of anti-body drug treating PAH in phase 1B trial - PRNewswire - October 27th, 2020 [October 27th, 2020]
- North America to Outshine the Global Slowdown in Cardiac Restoration Systems market between 2020 and 2030 - The Think Curiouser - November 12th, 2020 [November 12th, 2020]
- Age-Related Development of Cardiac Remodeling and Dysfunction in Young Black and White Adults: the Coronary Artery Risk Development in Young Adults... - November 25th, 2020 [November 25th, 2020]
- Adiponectin receptor 1 variants contribute to hypertrophic cardiomyopathy that can be reversed by rapamycin - Science Advances - January 13th, 2021 [January 13th, 2021]
- Longer Survival Seen in Heart Failure Stabilized Via Cardiac Resynchronization Therapy - The Cardiology Advisor - April 13th, 2021 [April 13th, 2021]
- Cardiac Dimensions Welcomes Robert White to its Board of Directors - PRNewswire - April 13th, 2021 [April 13th, 2021]
- [Full text] SIRT1 is Required for Exercise-Induced Beneficial Effects on Myocardia | JIR - Dove Medical Press - April 13th, 2021 [April 13th, 2021]
- Role of Pyroptosis in Diabetes and Its Therapeutic Implications | JIR - Dove Medical Press - May 25th, 2021 [May 25th, 2021]
- Epigenetic therapies for heart failure | VHRM - Dove Medical Press - May 25th, 2021 [May 25th, 2021]
- Are you at risk for sudden death, and can it be prevented? - Jamaica Observer - May 25th, 2021 [May 25th, 2021]
- Does a plant-based diet improve cardiac function? Here's the answer - Hindustan Times - June 21st, 2021 [June 21st, 2021]
- Early Use of Sacubitril/Valsartan Linked to Improved Cardiac Function Post AMI - AJMC.com Managed Markets Network - November 5th, 2021 [November 5th, 2021]
- Higher BP, LV Changes Seen in Children Conceived by ART - Medscape - November 5th, 2021 [November 5th, 2021]
- Regional Heterogeneity in Determinants of Atrial Matrix Remodeling and Association with Atrial Fibrillation Vulnerability Post-Myocardial Infarction -... - January 26th, 2022 [January 26th, 2022]
- 4 promising heart failure therapies interventional cardiologists should keep an eye on - Cardiovascular Business - May 7th, 2022 [May 7th, 2022]
- LEXEO Therapeutics Announces Data Presentations at the 25th American Society of Gene & Cell Therapy (ASGCT) Annual Meeting - Yahoo Finance - May 7th, 2022 [May 7th, 2022]
- Ventricular structure and function in hypertensive patients | IJGM - Dove Medical Press - May 7th, 2022 [May 7th, 2022]
- Effects of diabetes mellitus on left ventricular function and remodeling in hypertensive patients with heart failure with reduced ejection fraction:... - May 7th, 2022 [May 7th, 2022]
- Cardior Announces CE Marking of CardiorHealth miR-132 PCR Kit Used in Ongoing HF-REVERT Phase 2 Clinical Study - Business Wire - September 12th, 2022 [September 12th, 2022]