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Predictors of left atrial thrombus resolution in patients with mitral stenosis planned for percutaneous transvenous mitral commissurotomy(PTMC)
No full textMitral stenosis (MS) is a common finding in Rheumatic Heart Disease (RHD). The current
management of symptomatic mitral stenosis is Percutaneous Transvenous Mitral
Commissurotomy (PTMC) unless it is contraindicated. The presence of Left Atrial Thrombus
(LAT), however, is generally considered a contraindication to PTMC, leaving the open
surgery as the treatment option.
Left atrial thrombus occurs frequently in patients with Rheumatic Mitral Stenosis1
.Most of
Left Atrial thrombus occurs in Left Atrial Appendage(LAA)2. The association of LAT in
patients with MS and atrial fibrillation (AF) is well known3
. But it also occurs in patients
with sinus rhythm (SR). And patients in Sinus Rhythm (SR) of rheumatic mitral stenosis
were also noted to have larger LAA and poorer LAA contractile function3,4.This enhances
stagnation and thrombus formation in the Left atrial appendage or Left atrium. The presence
of thrombus increases the risk of systemic and peripheral embolism and it is a relative
contraindication for PTMC. Framingham study showed 17 fold increase in risk of stroke for
patients with AF and MS5. The reported incidence of LAT in severe Rheumatic MS is
between 10% and 25%6,7,8
. Various studies have shown that Transesophageal
Echocardiography(TEE) identifies Left atrial thrombus better than Transthoracic
Echocardiography(TTE). The presence of LAT in patients with mitral Stenosis may alter the
therapeutic approaches to the disease. In some circumstances, complete resolution of LAT
can be achieved with oral anticoagulant therapy (OAC), allowing patients to undergo PTMC
safely. Knowing the likelihood of LAT disappearance would help the physician to decide
whether to proceed with surgical repair or to continue oral anticoagulation until LAT
resolution and then to perform PTMC. The current management of severe MS is PTMC
unless contraindicated. After complete resolution of LAT following adequate anticoagulation,2
these patients with severe MS can undergo PTMC without any added risk. Especially a model
would help in predicting the likelihood of LA thrombus resolution, and hence, the treatment
plan can be altered accordingly. Hence it is very essential to develop a model to identify
patients who would respond to Oral anticoagulants on short term
Long term outcomes of bidirectional glenn and fontan procedures in a tertiary care cardiac centre in south india
No full textPatients with univentricular or biventricular atrioventricular(AV) connections can be
functionally univentricular, in which the dominant (single) ventricle provides the driving
force to both systemic and pulmonary circulations(1). Irrespective of the anatomic diagnosis,
the restoration of a normal preload, and optimization of afterload to the dominant ventricle
represents the fundamental principle in the management of these complex congenital heart
diseases.
The current staged approach to management involves an early neonatal palliation,
followed by stepwise reduction in preload to the single ventricle(SV)- the creation of a
bidirectional cavopulmonary anastomosis, followed by completion of the Fontan
circulation(2). These palliative surgeries are undertaken to route the systemic venous return
directly to pulmonary arteries (PAs). The bidirectional Glenn (BDG) anastomosis is most
frequently used as the 1st step in a staged palliation in preparation for a later total
cavopulmonary connection(TCPC). The blood from superior vena cava (SVC) is routed to
the pulmonary artery(PA) However, it may also be used in patients with hypoplastic right
ventricle(RV) and selected other lesions, such as Ebstein’s anomaly. It off loads the systemic
ventricle and is a direct source of blood supply to the pulmonary arteries facilitating their
growth. It is most commonly done in late infancy. It may also be performed as the final
palliation in older patients/ in borderline right ventricles/Ebsteins anomaly as part of 1.5
ventricle repair. Most of the patients undergo Fontan procedure on follow up so as to further
off load the systemic ventricle and direct the systemic venous blood totally to the pulmonary
arteries. The surgery involves routing of the blood from inferior vena cava (IVC) to the PA. It
is currently recommended by the age of 1.5 to 4 years. This staged approach gives the
ventricle the time to adapt and help in remodelling following reduction of the volume load.
The intermediate procedure prior to TCPC also helps to address other anatomic and 3
physiologic abnormalities (including atrioventricular valve regurgitation(AVVR), correction
of distorted PA anatomy).
Figure: The relative merits and demerits of BDG and Fontan surgeries
Both the procedures are at the best palliative in nature. There is a large amount of
literature regarding complications encountered on long term follow up of these patients. BDG
helps in offloading systemic ventricle and augments PA growth, however there is
desaturation and almost universal development of pulmonary arteriovenous
malformations(PAVMs)(3). Patients following Fontan surgery have normal saturation but it
is a state of preload deprivation and is fraught with ventricular dysfunction, protein losing
enteropathy (PLE), cirrhosis and arrhythmias in the long run(4). There are limited treatment
options(transplantation) if Fontan failure occurs.
Sree Chitra Tirunal Institute of Medical Sciences and Technology(SCTIMST) is a
tertiary care cardiac centre located in Thiruvananthapuram which caters to patients from
Kerala and the border districts of Tamil Nadu. There is a large cohort of SV patients who
were palliated with these surgeries in our Institute. We aim to report present-day outcomes
following BDG and Fontan procedures in children and young adults with various anomalies
and to examine the risk factors for mortality and morbidity. The ultimate goal is to identify
patients who are at high risk of failure early so that timely interventions may be planned
which may positively influence their survival.
BDG
• Offloading systemic
ventricle
• PA growth
• Demerits
– Desaturation
– PAVMs
FONTAN
• Normal saturation
• Unloads systemic ventricle
further
• Demerits
– Preload deprivation
– Ventricular dysfunction, PLE,
cirrhosis, effusions
– Need for 1 more surgery4
There is scarcity of data regarding the outcomes of BDG from India. It may serve as
the final stage of palliation in a large subgroup of patients where Fontan procedure is delayed
due to lack of resources, economic and social issues. We propose to analyze the long-term
survival, modes of death, and predictors of mortality in a large single-center cohort of
patients treated in SCTIMST with diverse forms of Fontan palliation
Effect of VEGF Expression in Bioengineered Human Adipose Derived Mesenchymal Stem Cells for Promoting Angiogenesis in Chronic Wound Healing
No full text
Study of haemodynamics of Chitra Valve in mitral position- a single centre experience
No full textIn India, a large number of people suffer Rheumatic heart disease and related
complications. It is estimated that six out of every 1000 children suffer Rheumatic fever
between the age of five and fifteen years. The major cause of long term morbidity and
mortality due to Rheumatic fever is the result of heart valve dysfunction. Valve
replacement is considered the therapy to avoid risk of heart failure and death.
Although mechanical heart valves (MHV) have evolved a level of universal
acceptance, they have never reached a level of performance comparable to that of the
natural valve of the heart. Consequently mechanical heart valve implantation is not
always an ideal solution. There is continual obligation to better understand the
mechanical behaviour of mechanical heart valves in vitro and in vivo, to study the effects
and presence of thrombosis, haemolysis, cavitation, transvalvular pressure fluctuations,
high level of stress and certainly the association and interaction of all these conditions.
Apparently the flow through pivoted leaflets of mechanical heart valves induces a
combination of flow characteristics, which are clearly dependent on the specific valve
design and orientation that could result too many pathological condition. All these
conditions reduce the efficiency of the heart being in a state far from natural. Clinical
practice has demonstrated that the orientation of MHV's greatly effects the postoperative
performance of the left ventricle.
The second most common heart operation is valve replacement surgery. Cardiac
valve are intended to fully replace a diseased natural valve and thus replacement has been
established clinical practice for more than four decades. Today more than 1.5 lakh valves
are replaced worldwide per year. The most commonly replaced valves are the mitral and
aortic valves due to the high pressure loads on the left atrium and left ventricle of the
heart. Any of the four valves can become either too leaky (regurgitation) or too tight
(stenotic). The two major problems related to the blood flow are thrombus formation and
haemolysis, which damage the red blood cells. It is well known that the shear stress in the fluid and the flow separation around the valve are blamed for such disastrous
phenomenon, therefore, it is obvious that there is a need for more effective heart valve to
be designed to present these types of situation from occurring
Bio-interactions and risks of engineered nanoparticles
No full textNano technological research offered uncountable opportunities for engineered nanoparticles (ENPs) in the field of biomedical, pharmaceutical, agricultural, cosmetics, textiles, automobiles and electronic industry. Large scale commercial production and use of nanoparticles with smaller size and characteristic physico-chemical properties enhance the possibility of amenable toxicity to the environment. Primary important species of the ecosystem like bacteria, algae, fishes and plants are at high risk with nanoparticle (NP) toxicity. ENP distributed in air, water and soil can directly affect the livelihood or even the existence of smaller organisms. In day-today life, human beings are getting exposed to thousands of NPs via dermal contact, inhalation or ingestion. Topical application of sunscreens and cosmetics containing ENPs has the potential to induce photo toxicity under ultra violet irradiation. ENP intentionally or non-intentionally enter into the body will affect the entire organ system and execute their toxicity even in reproduction and fetal developmental stages. Unfortunately the existing researches to evaluate the in vivo and in vitro toxic effects of ENPs are inefficient to give the exact nature and depth of toxicity. Hence an effort was made to discuss on the characteristics, classification, synthesis, applications and toxic potentials of various classes of commercially relevant ENPs along with a detailed review on currently available literatures
Prospective observational study for the evaluation of clinical and radiological correlates in patients undergoing surgery for vestibular schwannoma
No full textCerebellopontine angle (CPA) tumours comprise 5 to 10 percent of all intracranial
tumours. Around 90 % of all CPA tumours are vestibular schwannomas, which are
benign tumours of the vestibular portion of the vestibulocochlear nerve, arising from the
Schwann cells. They first originate in the intracanalicular part of the nerve and grow
slowly out into the cisterns. They present with unilateral sensorineural hearing loss with
poor speech discrimination (77 to 95 %), unilateral non pulsatile tinnitus (53 to 70%),
vestibular dysfunction, trigeminal nerve symptoms, cerebellar dysfunction, headache,
facial nerve dysfunction, raised intracranial pressure and lower cranial palsy. Long tract
signs are a late finding in patients with vestibular schwannomas and these have become
extremely rare in modern series. (1,2)
Long tract involvement may present with hyperactivity of ipsilateral deep tendon
reflexes, increased tone of the musculature and Babinski sign - extensor plantar response.
Rarely extremity weakness and ipsilateral sensory symptoms are found in a small subset
of patients. (1 - 10)
Diffusion tensor imaging of the brainstem allows delineation of the white matter tracts of
the brainstem. It allows subjective quantification of the directional diffusion of the water
in the white matter tracts. Lui et al found that in circumscribed posterior fossa primary
lesions there was a correlation between clinical weakness and higher mean diffusivity,
lower fractional anisotropy and lower transverse eigenvalue values. (55)This study can assess the subset of the patients with vestibular schwannomas who present
with long tract signs and their correlation with tractography findings preoperatively. The
intraoperative nature of the tumour and the histopathological characteristics will be noted
and the postoperative outcome with repeat imaging will be assessed. Through this study,
we objectively hope to define the less commonly studied manifestation of vestibular
schwannomas, the long tract signs - the size of the tumour beyond which they tend to
occur - both clinically and radiologically. There is scarcity of research correlating clinical
data with DTI imaging findings and the post operative follow up data, showing outcome
after resection. This study hopes to assess the utility of diffusion tensor imaging to
objectively quantify the involvement of long tracts in vestibular schwannomas and its
usefulness in predicting post operative outcome. The Principal Investigator of this study
regularly operates on vestibular schwannomas and we hope that this data will add on to
the understanding of the long tract involvement in vestibular schwannomas
Content validity of the newly developed risk assessment tool for religious mass gathering events in Indian settings (Mass Gathering Risk Assessment Tool-MGRAT).
No full textBackground: Risk assessment (RA) for mass gathering events is crucial to identify potential health hazards. It aids in planning and response activities specific to the event but is often overlooked by the event organizers. This paper reports the content validity process of a newly developed tool called Mass Gathering Risk Assessment Tool (MGRAT), which intends to assess the risks associated with religious mass gathering events in Indian settings. Methods: Qualitative approach was followed to identify the risks associated with mass gathering events and to identify the domains and items to be included in the RA tool. The draft tool was shared with six experts who were selected by the convenient method; selected experts were requested to assess the tool and give their comments about the domains, items, relevant responses, and overall presentation of the tool using content validity questionnaire. Content validity index and Fleiss kappa statistics were calculated to assess the agreement between multiple raters. Results: Agreement proportion expressed as scale-level content validity index (S-CVI) calculated by the averaging method is 0.92. S-CVI; calculated by universal agreement is 0.78. Fleiss kappa statistics to measure the agreement between multiple experts after adjusting the component of the chance agreement is 0.522 (95% CI: 0.417, 0.628, P value: 0.001). Conclusion: MGRAT is a valid tool, which has an appropriate level of content validity. As the number of raters increases, there will be difficulty in achieving consensus among all the items, which is the reason for lower Content Validity Index/Universal Average (CVI/UA) when compared with Content Validity Index/Average (CVI/Ave). Fleiss kappa statistics also indicated moderate agreement among the raters beyond the chance agreement, which also supports the appropriate content validity of MGRAT
Quantification of right atrial end-systolic volume and ejection fraction in children undergoing cardiac surgery with two dimensional transesophageal echocardiography
No full textLeft atrial (LA) end-systolic volume reflects the burden of left ventricular (LV)
diastolic dysfunction. LA end-systolic volume index of > 34 ml/m2
is associated with
adverse outcomes in patients, including a higher incidence of stroke, heart failure and
death.1-4 Recently, right atrial (RA) end-systolic volumes and RA ejection fraction (EF)
were quantified in healthy adult volunteers.5, 6 These data have now been incorporated in
the 2015 update on quantification of cardiac chambers and volumes.7
Children undergoing cardiac surgery may have right ventricular (RV) diastolic
dysfunction secondary to the effects of lesions causing either volume overload (atrial
septal defects [ASD]) or pressure overload (Tetralogy of Fallot [TOF]).8-10 RV diastolic
dysfunction may similarly affect the RA end-systolic volumes and RA EF. Therefore, it
would be useful to know the “normal” values of RA end-systolic volume and RA EF in
children. But such values may be difficult to obtain either in healthy children or in children
undergoing non-cardiac surgery (i.e., those without cardiovascular disease); this would
require additional imaging of the heart (often difficult without general Anaesthesiaesia)
and would be both unwarranted and unethical. Furthermore, values obtained in adults
may vary considerably from those in children.
Children with ventricular septal defect (VSD) may have similar RA/RV chamber
dimensions as compared to children without cardiovascular disease, since VSDs usually
lead to LA/ LV volume overload without affecting the right heart.
9 Technically, the blood
transits across the VSD into the pulmonary artery (PA). However, as both ventricles
contract simultaneously, the RV does not realize a volume overload in this situation. 3
Similarly, volume overload of the RA does not occur.
9 2-dimensional (2D)
echocardiography is now the standard monitoring of care for patients undergoing cardiac
surgery.11
Therefore, the primary aim of the study was to establish “normal” RA end-systolic
volume (indexed to body surface area) and RA EF in children using 2D echocardiography;
these values were obtained from the cohort of children undergoing VSD repairs. The
secondary aim of the study was to obtain the RA end-systolic volume and RA EF in
children with RA/RV volume overload (ASD) and RV pressure overload (TOF) to
determine if baseline differences existed between the three lesions.
Apart from abnormal hemodynamics, body size is the most powerful determinant
of the size of cardiovascular structures: all cardiovascular structures increase in size
parallel to somatic growth, a phenomenon known as cardiovascular allometry.
Expressing measurements in relation to body size allows a meaningful distinction
between normal and abnormal values in children.12
RA anatomy
The RA is the cardiac chamber that typically receives deoxygenated blood from
the systemic venous and coronary sinus return. Blood is then directed into the RV through
the tricuspid valve. During embryogenesis and development, after the right horn of the
sinus venosus incorporates into the RA, the valve of the sinus venosus divides the RA
into two chambers. A posterior smooth portion forms from the sinus venosus, and an
anterior muscular portion forms from the embryologic RA. The valve of the sinus venosus
usually regresses during weeks 9–15 of gestation, with the cranial portion forming the 4
crista terminalis and the caudal portion forming the valves of the inferior vena cava
(eustachian valve) and coronary sinus (thebesian valve). Looking at the three dimensional (3D) images of the heart, the RA is positioned to the right and
anteriorly, while the LA is situated to the left and posteriorly 13
The RA comprises of three components: appendage, the venous part (sinus
venarum) and the vestibule. The crista terminalis is a muscular ridge in the RA wall that
separates the smooth and muscular portions of the atrium. The eustachian valve primarily
serves to direct blood toward the fossa ovalis in fetal life. The thebesian valve prevents
reflux of RA blood into the coronary sinus.
The normal RA is a thin, complex 3D structure that serves as a passive conduit to
RV filling in early diastole and by active contraction during late diastole. When the
tricuspid valve is closed, it acts as a reservoir for systemic venous return. RA enlargement
has been considered as an early sign of RV diastolic dysfunction, where its increased
reservoir capacity compensates for diminished RV compliance.
14
Echocardiographic evaluation of the RA
The evaluation of the RA is less standardized than for the left heart, especially
because of different echocardiographic evaluation techniques and more complex
spatial anatomy of the right heart. The RA size and function measurement have been
described from the trans-thoracic apical four-chamber or subcostal views. Briefly, RA
long-axis is measured from the center of the tricuspid annulus to the center of the
superior RA wall, parallel to the interatrial septum. The RA minor axis is measured
between the mid-RA free wall to the interatrial septum, perpendicular to the long-axis. 5
RA area is traced at the end of ventricular systole, from the lateral aspect of the tricuspid
annulus to the interatrial septum following the atrial endocardium. The area between
the leaflets and annulus of the tricuspid valve, together with the superior and inferior
vena cava and RA appendage are excluded from RA area. From apical four-chamber
view, visual comparison of a RA that appears larger than LA is qualitative evidence of
chamber enlargement
