Comparative utility of omnipolar and bipolar electroanatomic mapping methods to detect and localize dual nodal substrate in patients with atrioventricular nodal reentrant tachycardia

BACKGROUND

Catheter-based slow pathway modification (SPM) for atrioventricular nodal reentrant tachycardia (AVNRT) is traditionally performed at empiric sites using anatomical landmarks and test ablation feedback within the triangle of Koch (TK). While studies have described more tailored techniques such as bipolar low voltage bridge (LVB) and wavefront collision identification, few have systematically compared the diagnostic yields of each and none have investigated whether omnipolar mapping technology provides incremental benefit. The objective of this study was to compare the utility of omnipolar and bipolar-derived qualitative and quantitative measurements in identifying and localizing dual AVN substrate in patients with versus without AVNRT.

METHODS

A retrospective case-control study of consecutive patients with paroxysmal supraventricular tachycardia undergoing electrophysiology study with both omnipolar and bipolar mapping from 2022-2023.

RESULTS

Thirteen AVNRT cases (median age 16.1 years, 512 TK points) were compared to nine non-AVNRT controls (median age 15.7 years, 332 TK points). Among qualitative variables, an omnipolar activation vector pivot, defined as a ≥45 degree change in activation direction within the TK, had the highest positive (81%) and negative predictive values (100%) for identifying AVNRT cases and had a median distance of 1 mm from SPM sites. Among quantitative variables, the optimal discriminatory performance for successful SPM sites was observed using bipolar voltage restricted to a peak frequency >340 Hz (c statistic 0.75).

CONCLUSIONS

Omnipolar vector pivot analysis represents an automated, annotation-independent qualitative technique that is sensitive and specific for AVNRT substrate and co-localizes with successful SPM sites. Bipolar voltage quantitatively describes SP anisotropy better than omnipolar voltage, and the addition of peak frequency signal analysis further optimizes the selection of SPM sites.

Contemporary Outcomes of Children With Acute Fulminant Myocarditis Supported With Peripheral Extracorporeal Membrane Oxygenation

Despite extracorporeal membrane oxygenation (ECMO) utilization in nearly 20% of cases, there are limited data in children with acute fulminant myocarditis (AFM) requiring ECMO. Herein we identify risk factors for death or heart transplant (HT) in children with AFM supported with ECMO, describe our experience with left atrial (LA) decompression, and depict long-term outcomes of survivors. We performed a retrospective cohort of patients <18 years with AFM (≤14 days of symptoms, rapid cardiogenic shock, and normal left ventricular [LV] size on presentation) supported with ECMO admitted to a single intensive care unit from 1997 to 2021. Among 28 patients (median age 9 years), 21 (75%) survived to discharge without HT. Patients were supported on ECMO for a median of 6 days. Three patients were bridged to HT with durable ventricular assist devices (VAD). Four patients died, two of whom were supported with VAD. At presentation, seven (25%) patients had high grade or complete atrioventricular block and eight (29%) had ventricular tachycardia. Before ECMO cannulation, 21 (75%) patients received CPR. The death/HT group had higher peak troponin levels (12.5 vs . 1.0 ng/ml, p = 0.02) and initial mean LA or pulmonary capillary wedge pressure (27 vs . 18 mm Hg, p = 0.03). Left atrial decompression was performed in 22 patients (79%). Twenty-two (79%) had acute myocarditis on endomyocardial biopsy. Among transplant-free survivors, 18 (86%) had normalization in LV function (median 7 days); the remaining three patients had persistent mild LV dysfunction at last follow-up (median 842 days). Transplant-free survival of pediatric patients with AFM supported on ECMO was 75% and associated with lower initial LA pressure and lower peak troponin. Recovery in ventricular function among survivors was rapid and durable.

Pediatric antiarrhythmics and toxicity: A clinical review

Antiarrhythmic medications are fundamental in the acute and chronic management of pediatric arrhythmias. Particularly in the pediatric patient population, associated antiarrhythmic toxicities represent important potential adverse effects. Emergency medicine clinicians must be skilled in the detection, workup, and management of antiarrhythmic toxicity. This is a clinical review of the indications, pharmacology, adverse effects, and toxicologic treatment of antiarrhythmics commonly used in the pediatric patient population.

Risk Factors for Adverse Outcomes in Term Infants with CHD and Definitive Necrotising Enterocolitis

OBJECTIVES

To define the incidence of definitive necrotising enterocolitis in term infants with CHD and identify risk factors for morbidity/mortality.

METHODS

We performed a 20-year (2000-2020) single-institution retrospective cohort study of term infants with CHD admitted to the Boston Children's Hospital cardiac ICU with necrotising enterocolitis (Bell's stage ≥ II). The primary outcome was a composite of in-hospital mortality and post-necrotising enterocolitis morbidity (need for extracorporeal membrane oxygenation, multisystem organ failure based on the paediatric sequential organ failure assessment score, and/or need for acute gastrointestinal intervention). Predictors included patient characteristics, cardiac diagnosis/interventions, feeding regimen, and severity measures.

RESULTS

Of 3933 term infants with CHD, 2.1% (n = 82) developed necrotising enterocolitis, with 67% diagnosed post-cardiac intervention. Thirty (37%) met criteria for the primary outcome. In-hospital mortality occurred in 14 infants (17%), of which nine (11%) deaths were attributable to necrotising enterocolitis. Independent predictors of the primary outcome included moderate to severe systolic ventricular dysfunction (odds ratio 13.4,confidence intervals 1.13-159) and central line infections pre-necrotising enterocolitis diagnosis (odds ratio 17.7, confidence intervals 3.21-97.0) and mechanical ventilation post-necrotising enterocolitis diagnosis (odds ratio 13.5, confidence intervals 3.34-54.4). Single ventricle, ductal dependency, and feeding related factors were not independently associated with the primary outcome.

CONCLUSIONS

The incidence of necrotising enterocolitis was 2.1% in term infants with CHD. Adverse outcomes occurred in greater than 30% of patients. Presence of systolic dysfunction and central line infections prior to diagnosis and need for mechanical ventilation after diagnosis of necrotising enterocolitis can inform risk triage and prognostic counseling for families.

Heating and storage of structured acylglycerols with succinyl-linked stigmasterol residue does not cause negative chemical or biological changes

Four structured acylglycerols with stigmasterol bonded by a succinyl linker were investigated and their stability were analyzed. Samples were heated to 60 °C and kept at that temperature to simulate storage, and to 180 °C to simulate frying conditions. The degradation of the synthesized compounds and formed derivatives was determined, and their cytotoxicity and genotoxicity on normal human cells from the digestive system was determined. Holding at 180 °C resulted in greater degradation of the compounds than holding at 60 °C. The most stable compound in each sample proved to be one with oleic acid in its structure-1,3-dioleoyl-2-stigmasterylsuccinoyl-sn-glycerol (DO2SSt) at 60 °C and 1,2-dioleoyl-3-stigmasterylsuccinoyl-sn-glycerol (DO3SSt) at 180 °C. These results indicate that the type of fatty acid in the molecule is more important than its position in the glycerol structure. None of the diacylmonostigmasterylsuccinoyl-sn-glycerols (DASStGs) before or after heating exhibited cytotoxic or genotoxic potential to small intestine and colon mucosa cells.

Medical cardioversion of atrial fibrillation and flutter with class IC antiarrhythmic drugs in young patients with and without congenital heart disease

INTRODUCTION

The use of flecainide and propafenone for medical cardioversion of atrial fibrillation (AF) and atrial flutter/intra-atrial reentrant tachycardia (IART) is well-described in adults without congenital heart disease (CHD). Data are sparse regarding their use for the same purpose in adults with CHD and in adolescent patients with anatomically normal hearts and we sought to describe the use of class IC drugs in this population and identify factors associated with decreased likelihood of success.

METHODS

Single center retrospective cohort study of patients who received oral flecainide or propafenone for medical cardioversion of AF or IART from 2000 to 2022. The unit of analysis was each episode of AF/IART. We performed a time-to-sinus rhythm analysis using a Cox proportional hazards model clustering on the patient to identify factors associated with increased likelihood of success.

RESULTS

We identified 45 episodes involving 41 patients. As only episodes of AF were successfully cardioverted with medical therapy, episodes of IART were excluded from our analyses. Use of flecainide was the only factor associated with increased likelihood of success. There was a statistically insignificant trend toward decreased likelihood of success in patients with CHD.

CONCLUSIONS

Flecainide was more effective than propafenone. We did not detect a difference in rate of conversion to sinus rhythm between patients with and without CHD and were likely underpowered to do so, however, there was a trend toward decreased likelihood of success in patients with CHD. That said, medical therapy was effective in >50% of patients with CHD with AF.

Hypertrophic Cardiomyopathy and Ventricular Preexcitation in the Young: Cause and Accessory Pathway Characteristics

BACKGROUND

The cause of hypertrophic cardiomyopathy (HCM) in the young is highly varied. Ventricular preexcitation (preexcitation) is well recognized, yet little is known about the specificity for any cause and the characteristics of the responsible accessory pathways (AP).

METHODS

Retrospective cohort study of patients <21 years of age with HCM/preexcitation from 2000 to 2022. The cause of HCM was defined as isolated HCM, storage disorder, metabolic disease, or genetic syndrome. Atrioventricular AP (true AP) were distinguished from fasciculoventricular fibers (FVF) using standard invasive electrophysiology study criteria. AP were defined as high risk if any of the following were <250 ms: shortest preexcited RR interval in atrial fibrillation, shortest paced preexcited cycle length, or anterograde AP effective refractory period.

RESULTS

We identified 345 patients with HCM and 28 (8%) had preexcitation (isolated HCM, 10/220; storage disorder, 8/17; metabolic disease, 5/19; and genetic syndrome, 5/89). Six (21%) patients had clinical atrial fibrillation (1 with shortest preexcited RR interval <250 ms). Twenty-two patients underwent electrophysiology study which identified 23 true AP and 16 FVF. Preexcitation was exclusively FVF mediated in 8 (36%) patients. Five (23%) patients had AP with high-risk conduction properties (including ≥1 patient in each etiologic group). Multiple AP were seen in 8 (36%) and AP plus FVF in 10 (45%) patients. Ablation was acutely successful in 13 of 14 patients with recurrence in 3. One procedure was complicated by complete heart block after ablation of a high-risk midseptal AP. There were significant differences in QRS amplitude and delta wave amplitude between groups. There were no surface ECG features that differentiated AP from FVF.

CONCLUSIONS

Young patients with HCM and preexcitation have a high likelihood of underlying storage disease or metabolic disease. Nonisolated HCM should be suspected in young patients with large QRS and delta wave amplitudes. Surface ECG is not adequate to discriminate preexcitation from a benign FVF from that secondary to potentially life-threatening AP.

Retroflexed catheter course reduces the risk of right free wall accessory pathway recurrence

INTRODUCTION

Accessory atrioventricular pathways (APs) may mediate atrioventricular reciprocating tachycardia and, in some cases, have the potential to conduct atrial tachycardia rapidly, which can be life threatening. While catheter ablation can be curative, ablation of right free wall APs is associated with a high rate of recurrence, likely secondary to reduced catheter stability along the right free wall atrioventricular groove. We sought to identify characteristics associated with a lower rate of recurrence and hypothesized ablation lesions placed on the ventricular side of the atrioventricular groove using a retroflexed catheter approach would decrease rates of recurrence.

METHODS AND RESULTS

Retrospective chart review of patients who underwent catheter ablation of a right free wall AP from January 1, 2008 through June 1, 2021 with >2 months follow up. Cox proportional hazards regression was used to identify relationships between predictor variables and AP recurrence. We identified 95 patients who underwent ablation of 98 right free wall APs. Median age was 13.1 years and median weight at ablation was 52.3 kg. Overall, 23/98 (23%) APs recurred. Use of a retroflexed catheter course approaching the atrioventricular groove from the ventricular aspect was associated with reduced risk of AP recurrence with (univariable hazard ratio of 0.10 [95% confidence interval: 0.01-0.78]), which remained significant in multiple two variable Cox proportional hazards models.

CONCLUSION

Use of a retroflexed catheter course is associated with a reduced likelihood of AP recurrence. This approach results in improved catheter stability and should be considered for ablation of right free wall APs.

Current management of inherited arrhythmia syndromes associated with the cardiac ryanodine receptor

PURPOSE OF REVIEW

Gain-of-function variants in the gene encoding the cardiac ryanodine receptor ( RYR2 ) are associated with catecholaminergic polymorphic ventricular tachycardia (CPVT). The exercise stress test (EST) has long been fundamental in diagnosis and management, but recent work has further explored its role. A new entity termed calcium release deficiency syndrome (CRDS) has been associated with loss-of-function RYR2 variants and a different arrhythmic phenotype.

RECENT FINDINGS

Standard EST is not perfectly reproducible with regards to provocation of arrhythmia in CPVT. A newly described burst EST protocol may be more sensitive in this regard. Nadolol is the most effective beta blocker in CPVT, though arrhythmic events remain frequent and dual therapy with flecainide and/or left cardiac sympathetic denervation may add protection. A recent report renews debate regarding the use of implantable defibrillator therapy in CPVT. CRDS is characterized by later age of presentation, normal/near normal EST, and ventricular arrhythmia induced by a novel ventricular stimulation protocol.

SUMMARY

Burst EST may aid in the diagnosis and management of CPVT. Nadolol is the preferred beta blocker in CPVT, and consideration should be given to early dual therapy. CRDS should be suspected in patients with arrhythmic events, rare RYR2 variants, and a phenotype inconsistent with CPVT.

Thermo-oxidative stability and safety of new acylglycerols with stigmasterol residue: Effects of fatty acids saturation and position in the glycerol backbone

The safety and thermoxidative stability of new diacyl-stigmasterylcarbonoyl-sn-glycerols (DAStGs) with two molecules of palmitic or oleic acids and one molecule of stigmasterol at the sn-2 or sn-3 position were studied. After heating to 60 °C, the compounds with stigmasterol at the sn-2 position were more stable than those with stigmasterol at the sn-3 position. The lowest level of degradation of stigmasterol after heating to 180 °C was detected for both compounds with oleic acid, followed by the samples with palmitic acid. The high content of SOPs, especially triolSt, as well as the high level of dimers showed the most effect on the cytotoxicity of DAStGs heated at both temperatures. DAStGs with oleic acid at sn-1,3 and stigmasterol at sn-2 position were the most stable compounds. Both oleic acid and the location of stigmasterol in the middle of the glycerol molecule play an important role in increasing the thermoxidative stability of stigmasterol.

Incremental value of myocardial work in predicting beneficial response to aortic valve replacement in patients with aortic stenosis

 

The predictors of favorable clinical response to aortic valve replacement (AVR) in aortic stenosis (AS) are still insufficiently defined. The increased LV afterload in AS affects the interpretation of the majority of LV systolic indices, which are load-dependent. The estimation of myocardial work (MW) is a newly developed approach, which, allowing correction of global longitudinal strain (GLS) for LV afterload, gives a more adequate insight into the intrinsic LV contractility.

Aim

To investigate whether the assessment of MW can improve the prediction of clinical and neurohormonal improvement post AVR in patients with AS.

Methods

We evaluated 126 patients (75±9 years) with severe AS who underwent transcatheter AVR (n=100) or surgical AVR (n=26). Transthoracic echocardiography, blood sampling and 6 min walk test (6MWT) were performed pre and 3 months post AVR. The following indices of MW were assessed: global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE).

Results

Post-AVR changes in the clinical and echocardiographic profile are presented in Table. Post-treatment increase in 6MWT distance was noted in 95 patients, and decrease in NT-proBNP in 94 patients. In multivariable analysis including clinical parameters and echocardiographic indices of cardiac function, morphology and aortic valve hemodynamic, baseline GWW was the only independent echocardiographic predictor of post-AVR improvement in 6MWT distance (beta=−0.24, SE 0.09, p=0.01), whereas baseline GWE was, in addition to tricuspid regurgitation pressure gradient (TRPG) and E/e' ratio, independently associated with the post-AVR decrease in NT-proBNP (beta=0.27, SE 0.09, p=0.004).

Conclusions

In patients with severe AS undergoing AVR, higher values of GWW do not favor post-treatment functional improvement as assessed by 6MWT. The beneficial neurohormonal response to AVR is more pronounced in patients with less efficient LV contraction at baseline.

Funding Acknowledgement

Type of funding sources: None.

Thermo-oxidative stability of asymmetric distigmasterol-modified acylglycerols as novel derivatives of plant sterols

The study investigated the thermo-oxidative stability of distigmasterol-modified acylglycerols as a new structured acylglycerols. Samples were heated at 60 and 180 °C for 8 h. Their percentage degradation and products formed during heating were compared with free stigmasterol and stigmasteryl esters. The remaining of stigmasterol and fatty acid parts, the formation of stigmasterol oxidation products and the composition of polar and non-polar fractions were analysed using chromatographic methods. The cytotoxicity and genotoxicity were determined with the use of an MTT test and a comet assay, respectively. The highest stability during heating was observed for 2,3-distigmasterylsuccinoyl-1-oleoyl-sn-glycerol (dStigS-OA) and the lowest for 2,3-distigmasterylcarbonoyl-1-oleoyl-sn-glycerol (dStigC-OA). Data showed that the formation of thermo-oxidative degradation products is affected by the temperature and chemical structure of lipids present in the molecule. The dStigMAs bonded by a succinate linker and products formed during their thermo-oxidation showed no cytotoxic or genotoxic activity to normal human cells.

Activity During the COVID-19 Pandemic in Children with Cardiac Rhythm Management Devices

Decreased physical activity is associated with cardiovascular, metabolic and mental health disease. While decreases in physical activity during the COVID-19 pandemic have been described in the general population, there is a paucity of data regarding children with underlying cardiovascular disease. We hypothesized there would be a decrease in physical activity at the onset of the COVID-19 pandemic. Performed a single-center, retrospective cohort study of children aged < 19 years with cardiac rhythm management devices. Patients were included if they had device-measured physical activity data from > 80% of dates from February 3, 2020 through June 30, 2020. Patients with significant neurologic/neuromuscular disease were excluded. We identified 144 patients with a median age of 15.4 years. 47% were female. 34% had congenital heart disease, 20% had cardiomyopathy, 19% had an inherited arrhythmia syndrome and 5% had atrioventricular block without congenital heart disease. 47% of patients had an implantable loop recorder, 29% had a permanent pacemaker and 24% had an implantable cardioverter-defibrillator. We observed a significant decrease in device-measured physical activity from baseline (February 3-March 9), with up to a 21% decrease in physical activity during mid-March through early May. Activity levels returned to pre-pandemic levels in June. Physical activity sharply declined in children with cardiac rhythm management devices at the onset of the COVID-19 pandemic. These data highlight the importance of finding strategies to maintain physical activity during the current pandemic and future public health crises.

Hemodynamic effects of balloon pulmonary angioplasty for the treatment of total and subtotal pulmonary artery occlusions in inoperable chronic thromboembolic pulmonary hypertension

Background

Balloon pulmonary angioplasty (BPA) has become a therapeutic option for inoperable chronic thromboembolic pulmonary hypertension (CTEH). Despite significant improvement in the technique, treatment of subtotal (STO) and total (TO) pulmonary artery occlusions with BPA may pose risk, but the efficacy is unknown.

Aim

We aimed to study to assess safety and efficacy of BPA in STO/TO.

Methods

We included consecutive patients with inoperable CTEPH, who underwent BPA treatment. To evaluate the efficacy and safety we grouped all BPA sessions into those in which recanalization of at least one STO or TO was performed and into those without. The primary efficacy outcome was improvement in pulmonary vascular resistance (PVR) in BPA sessions with STO/TO recanalization as compared to those without.

Results

We analyzed 169 BPA sessions in 50 CTEPH patients. Out of a total number of 832 lesions subjected for BPA, 168 were classified as STOs or TOs [129 (15,5%) and 39 (4,7%) respectively]. Three (2,3%) STOs and 8 (20,5%) TOs were not recanalized despite repeated attempts. There were 90 BPA sessions with at least one STO/TO recanalization. Racanalization of at least one STO/TO was associated with a trend towards PVR improvement as compared to non-STO/TO BPAs (−69±162 vs −38±135 dyn s cm–5, p=0,19). Recanalization of STO/TO at the level of segmental pulmonary artery as compared to subsegmental-only STO/TO recanalizations or no-STO/TO recanalization was associated with significant PVR improvement (−126±192 vs −38±135 dyn s cm–5, p=0.007). The rate of complications was similar in STO/TO and non-STO/TO BPA sessions (14.4% vs 12.6%, p=0.56).

Conclusions

The use of BPA for the recanalization of subtotal and total PA occlusions is safe and effective. Recanalization of segmental STO/TOs leads to significant improvement in PVR.

Funding Acknowledgement

Type of funding sources: None.

Surgical Correction of Scoliosis in Children with Severe Congenital Heart Disease and Palliated Single Ventricle Physiology

STUDY DESIGN

Case series.

OBJECTIVE

In this study we focus on this group, and describe the largest cohort to date of single ventricle patients undergoing surgical correction of scoliosis at a single institution.

SUMMARY OF BACKGROUND DATA

Outcomes of spinal surgery for patients with congenital heart disease (CHD) have evolved and most affected patients have uncomplicated procedures. The risk of perioperative complications remains highest in patients with single ventricle ("Fontan") physiology.

METHODS

We reviewed patients with single ventricle CHD and operative scoliosis repair over a 25-year span. Patients who had undergone a Fontan, bidirectional Glenn, and/or Kawashima procedure before operative scoliosis repair were included. Patients were excluded if they lacked preoperative cardiac care and/or sufficient medical history at our institution.

RESULTS

Twenty-three patients were included. The average age at surgery was 13.6 years (range, 5-23). Seventy percent of the cohort was female (16/23). The majority of patients underwent a Fontan before scoliosis surgery (20/23, 87%). Patients without intraoperative tranexamic acid (TXA) had a 67% complication rate (8/12) versus 36% (4/11) in those with intraoperative TXA (P = 0.29). There was a significant difference in estimated blood loss by weight (cc/kg) between non-TXA and TXA patients (P = 0.016). Twelve patients experienced complications (52%), all of which occurred postoperatively. There were no deaths, cerebrovascular events, adverse perioperative cardiac or hemodynamic complications, or wound infections. Using the Clavien-Dindo-Sink classification for postoperative complications, four patients had serious adverse events, including one permanent neurologic deficit.

CONCLUSION

Spinal surgery for scoliosis has been performed in selected patients with single ventricle physiology at a single institution without mortality for 25 years. Operative blood loss may be reduced by routine use of TXA. Complications occur most commonly in the postoperative period, and can include pleural effusion.Level of Evidence: 4.

Adverse Perioperative Events in Children with Complex Congenital Heart Disease Undergoing Operative Scoliosis Repair in the Contemporary Era

Scoliosis is common in children with congenital heart disease (CHD) and may have deleterious effects on quality of life and hemodynamics. Relatively little is known about the outcomes of spinal fusion for scoliosis repair in children with complex CHD. We reviewed all cases of children with CHD undergoing first time spinal fusion excluding those with minor CHD between 1995 and 2015. Seventy-eight patients were identified and included in the study. 97.4% of patients included had undergone prior cardiac surgery and sixteen patients had single ventricle circulations. 17.9% of patients experienced a significant perioperative event defined as an aggregate of the presence of any of the following: need for early unanticipated reoperation, neurologic deficit, postoperative bleeding requiring intervention, end organ dysfunction, or death. There were no deaths in our cohort. 38.5% of patients experienced any adverse event, the majority of which were related to perioperative fluid shifts. Larger preoperative Cobb angle and longer length of spinal fusion were associated with increased risk of significant perioperative event while larger preoperative Cobb angle and longer length of spinal fusion, older age at time of surgery, single ventricle circulation, cyanosis and patients taking cardiac medications at the time of surgery were more likely to experience any adverse event. Operative repair of scoliosis in children with complex CHD has been performed without mortality over a 20-year period in a single institution, albeit with a higher rate of perioperative complication than is seen in the general pediatric population. Patients with large preoperative Cobb angles and cyanotic single ventricle circulations appear to be at the highest risk for perioperative complications.

Vitamin D deficiency in the spontaneously hypertensive heart failure [SHHF] prone rat

BACKGROUND AND AIMS

Vitamin D deficiency has been associated with the etiology and pathogenesis of heart disease including congestive heart failure. We previously observed cardiac hypertrophy in vitamin D deficient rats and vitamin D receptor knockout mice. These studies indicate that the absence of vitamin D-mediated signal transduction and genomic activation results in increased sensitivity of the heart to ionotropic stimuli and cardiomyocyte hypertrophy. This study's aim is to investigate the relationship between vitamin D status and the heart failure phenotype in the rat.

METHODS AND RESULTS

Vitamin D status was assessed by measuring 25-hydroxyvitamin D levels and related to heart weight in young, middle-aged and aging spontaneously hypertensive, heart failure (SHHF) prone rats. We also measured the effects of the vitamin D hormone,1,25(OH)(2)D(3), on cardiac function in SHHF rats. Cardiac hypertrophy in this model of the failing heart increased with age and related to decreasing vitamin D status. Vitamin D deficiency presented after cardiac hypertrophy was first observed. Additionally, we found that 1,25(OH)(2)D(3) treatment between 4.0 and 7.0 months of age prevented cardiac hypertrophy and permits decreased workload for the heart while allowing adequate blood perfusion and pressure, resulting in reduced cardiac index.

CONCLUSIONS

Our findings suggest that low vitamin D status is associated with the progression and final terminal phase of the heart failure phenotype and not with initial heart hypertrophy. Also, we report that in the vitamin D sufficient SHHF rat, 1,25(OH)(2)D(3) treatment provided protection against the progression of the heart failure phenotype.

Pivotal karyometric measurements in different types of cardiomyopathic morphology: study of hearts explanted from transplant recipients

BACKGROUND

Morphometric studies based on the measurement of cardiocyte nuclei have focused on progressive hypertrophy rather than shape, which is a deciding factor for the diagnosis of hypertrophy in myocardial diseases. The aim of this research was to demonstrate how the digital morphology of cardiocyte nuclei change correlated with the type of myocardial pathology.

MATERIALS AND METHODS

The study groups encompassed 7 hearts with dilated cardiomyopathy (DCM) and 8 hearts with ischemic heart disease (IHD) which were explanted. A comparative group consisting of myocardial hypertrophy was contrasted with a control group of donor heart fragments. Cardiocyte nuclei were evaluated morphometrically on histologic slides. We calculated the nuclear area, length, breadth, perimeter, roundness, elongation, fullness factors, and nuclear chromatin mean gray level. The results were subjected to discriminant analysis.

RESULTS

All karyometric measurements analyzed by backward discriminant analysis showed only 2 powerful factors: nuclear breadth and chromatin mean gray level. The Mahalanobis distance showed the proximity of control and hypertrophy groups, whereas differences between IHD and DCM were nonsignificant.

CONCLUSION

The lack of karyometric differences between IHD and DCM suggested a common morphologic response for long-lasting progressive injury. The main morphologic differences were dependent on nuclear chromatin activity/stainability and nuclear breadth, suggesting darker and thinned nuclei in normal and adaptative stages and irregular brighter nuclei in cardiomyopathies.

Differences in antiapoptotic, proliferative activities and morphometry in dilated and ischemic cardiomyopathy: study of hearts explanted from transplant recipients

BACKGROUND

Antiapoptotic as well as replacement and proliferative mechanisms take place in the myocardium in dilated cardiomyopathy (DCM) and ischemic heart disease (IHD). We sought to estimate antiapoptotic, proliferative and replacement activities in cardiomyopathies.

MATERIALS

The study groups included seven hearts with DCM and eight with IHD, which had been explanted at the time of transplantation. The comparator group consisted of cases of myocardial hypertrophy and the control group, donor fragments.

METHODS

Antiapoptotic and proliferative responses were determined immunohistochemically as Bcl-2 and Ki67 expression by semiquantitative assessment of the intensity of staining. We also measured and statistically analyzed the integrative morphometric measurements of the fraction of fibrosis area, the nucleosarcoplasmic ratio, and cardiocyte diameter.

RESULTS

No Bcl-2 expression was observed in the controls. The strongest reaction was seen in the DCM group, then in the IHD, and in the comparator group of myocardial hypertrophy. Proliferative activity was seen only in endocardial and interstitial fibroblasts in DCM and IHD cases. The cardiocyte diameter showed no statistical association between myocardial hypertrophy and IHD, or IHD and DCM, whereas the nucleosarcoplasmic ratios were significantly different from control groups for all comparisons. Myocardial fibrosis showed the highest values in DCM and IHD. Discriminant analysis showed the value of interstitial fibrosis and cardiocyte diameter to categorize the analyzed groups.

CONCLUSIONS

Antiapoptotic Bcl-2 activity seemed to play an important role in cardiocyte preservation, while proliferative activity was resticted to interstitial connective tissue cells as a replacement process. Myocardial Bcl-2 expression, the extent of myocardial fibrosis, and cardiocyte diameter may serve as additional diagnostic tools to differentiate cardiomyopathies.

Cardiocyte nuclear chromatin density correlates with transplanted heart left ventricular mass

INTRODUCTION

Cardiocyte hypertrophy is accompanied by polyploidy, seen as a decrease in chromatin density in the enlarged nucleus. Repeated biopsies of a transplanted heart offer the possibility of a dynamic evaluation of these phenomena. The aim of this work was an evaluation of cardiocyte nuclear chromatin density in transplanted hearts during long-term follow-up.

MATERIALS AND METHODS

The material encompassed myocardial biopsy specimens taken during the first week, first month, and then on an annual basis up to 10 years after surgery. Only biopsy specimens with no rejection were considered (grade "0" International Society for Heart and Lung Transplantation [ISHLT] 122 biopsy specimens). The control group consisted of 7 donor heart specimens. We evaluated the optical density-mean gray level-of cardiomyocyte nuclear chromatin. We determined correlations of this index with the nuclear area, and with left ventricle ultrasound measurements, using correlation analysis.

RESULTS

The chromatin mean gray level decreased with time, correlating positively with interventricular septum thickness, left ventricle posterior wall diameter, and left ventricular mass. Analysis of individual periods showed a significant positive correlation of the mean grey level with the cardiocyte nuclear surface in year 3, 4, and 9 after transplantation, thereby suggesting the occurrence of polyploidy at those times. The significant negative correlation of these values (1 week and 1 year) indicated normalization of early cardiocyte hypertrophy.

CONCLUSIONS

With the passage of time chromatin condenses, leading to pyknosis. The activity of cardiocyte chromatin correlated with left ventricular hypertrophy. Compensatory cardiomyocyte polyploidy is a periodical phenomenon.

Remodeling of human transplanted myocardium in ten-year follow-up: a clinical pathology study

Remodeling taking place in transplanted myocardium leads to a change in the number of cardiocytes. Ultrasound measurements and biopsy evaluation should reflect their loss and compensation. We sought to evaluate the morphology of the transplanted heart upon long-term follow-up.

MATERIAL AND METHODS

Myocardial biopsies were obtained in the first week, first month, and then annually for 10 years from transplantation that did not show rejection (grade "0" ISHLT, 122 biopsies). The control group encompassed 7 donor heart fragments. Proliferation in biopsies was evaluated with Ki67 (M7240, DAKO), cardiocyte hypertrophy by measuring their diameter, the surface area of the nuclei, nuclear-sarcoplasmic index, and stromal fibrosis evaluated as the surface area fraction. Ultrasound measurements included diastolic thickness of the interventricular septum, posterior wall of the left ventricle, and left ventricular mass. The correlation of measurements with time from transplantation was evaluated using Spearman's test.

RESULTS

A positive Ki67 reaction was observed in fibroblasts and endothelial cells. The increased cardiocyte nuclear area correlated with the time elapsed since transplantation (r = 0.2; P < .05) with a simultaneous decrease in cardiocyte thickness (r = -0.3; P < .05), without changes in the nuclear-cytoplasmic index (r = 0.02; P > .05). Stromal fibrosis also increased (r = 0.1; P < .05). Ultrasound measurements of the left ventricle showed a decreased tendency with the passage of time (r = -0.2 to -0.3; P < .05).

CONCLUSION

A transplanted heart does not undergo hypertrophy but rather fibrous atrophy with apparent compensatory hypertrophy of the cardiomyocytes.

Cardiocyte nucleus shape as an indicator of heart graft aging

Morphometric publications based on the measurement of cardiocyte nuclei indicated their progressive hypertrophy ignoring, however, their shape, which is a deciding factor for the microscopic-based diagnosis of hypertrophy. We sought was to demonstrate how the shapes of cardiocyte nuclei change over time and correlate them with the thickness of the interventricular septum, (IVS) the biopsy site.

MATERIAL

We evaluated myocardial biopsies taken in the first week, first month, and then annually until posttransplant year 10. Only biopsies with no rejection were considered: grade "0" ISHLT (122 biopsies). The control group encompassed fragments from seven donor hearts.

METHODS

Cardiomyocyte nuclei were evaluated morphometrically. We calculated the length, breadth, perimeter, roundness, elongation, and fullness factors for correlation with the IVS thickness, and selected indices. The relationships between karyometry and IVS thickness (measured by ultrasound) as well as time were calculated by Spearman's correlation test.

RESULTS

Among the examined indices, only nuclear length did not correlate significantly with follow-up time. Among the remaining indices, the strongest correlations with time were observed with regard to breadth (r = 0.214), perimeter (r = 0.150), roundness (r = -0.06) and fullness (r = 0.06), and finally elongation (r = 0.02). The decreasing thickness of the interventricular septum (r = -0.31) showed a weak correlation only with the cardiocyte nuclear length (r = -0.05).

CONCLUSION

Graft aging imitates hypertrophy inasmuch as cardiocyte nuclei become wider despite the decreased thickness of the interventricular septum. Therefore, karyometric measurements do not reflect myocardial morphology.

Use of sildenafil in heart transplant recipients with pulmonary hypertension may prevent right heart failure

PURPOSE

We performed a short-term outcome analysis of orthotopic heart transplantation (OHT) in patients with pulmonary hypertension (PH) treated perioperatively with oral sildenafil.

METHODS

PH (pulmonary vascular resistance > 2.5 Wood units, and/or transpulmonary gradient > 12 mmHg) was diagnosed in 6 of 25 (group A) heart transplant recipients operated in 2006. This group of patients underwent a modified medication protocol including perioperative administration of oral sildenafil: 50 mg before followed by 50 or 25 mg TID after heart transplantation. Sildenafil treatment was discontinued 10 to 14 days post OHT, after stepwise dose reduction. During the ICU stay all patients underwent circulatory monitoring of pulmonary and systemic pressures and resistance as well as transthoracic echocardiogram (TTE) evaluation.

RESULTS

Perioperative oral sildenafil administration in PH patients undergoing OHT was associated with good short-term outcomes in the majority of transplanted patients (4/6). Sildenafil treatment reduced pulmonary resistance and pressures with a low rate of hemodynamic instability among OHT patients.

CONCLUSIONS

Pharmacologic perioperative reduction of PH improves the short-term prognosis for successful OHT. One may speculate whether sildenafil treatment transplant recipients with PH would be associated with long-term improvement of pulmonary vascular status, therefore leading to extended life-expectancy and improved outcomes.

The effect of Epstein-Barr virus infection on medium-term survival after orthotopic heart transplantation

Our aim was to assess the medium-time results after orthotopic heart transplantation (OHT) depending on the serostatus of heart transplant recipients at the time of transplantation.

MATERIALS AND METHODS

We enrolled 120 patients in this retrospective study including 107 males and an overall mean age of 49.1 +/- 8.6 years ischemic heart disease (IHD) was the diagnosis before OHT in 46%. The mean follow-up was 48 months. The first diagnostic coronary angiography was routinely preformed at 1 year after OHT, and then every second year. We evaluated every incidence of a change in the coronary arteries, the presence of significant stenosis (requiring percutaneous coronary intervention), acute myocardial infarction, death, or retransplantation. Using indirect immunofluorescence assays we detected Epstein-Barr virus (EBV) antigenemia by identification of antibodies against early antigens of EBV (EA) of IgM and IgG classes as well as IgG antibodies against nuclear antigen of EBV (EBNA). Since April 2001 all three types of antibodies were routinely investigated on admission to the hospital for OHT.

RESULTS

At the time of transplantation, IgM-EA antibodies were detected in 17 (14%) patients, IgG-EA in 35 (29%), and IgG-EBNA in 113 (94%). Survival rate, incidence of cardiac allograft vasculopathy and death, as a function of the serostatus of the heart recipient at the time of transplantation were estimated by Kaplan-Meier curves; the results were compared by log-rank tests. The findings among IgM EA, IgG EA, and IgG EBNA-positive and -negative groups were statistically comparable.

CONCLUSION

Infection with EBV before OHT did not worsen the prognosis over the first 4 years after transplantation.

Fresh forage and solin supplementation on conjugated linoleic acid levels in plasma and milk

Two experiments were run concurrently to determine the effect of fresh forage consumption on the production and proportions of plasma and milk fat vaccenic acid (VA), conjugated linoleic acid (CLA), and linolenic acid in diary cattle. In experiment 1, the cows consumed 50, 65, and 80% of their feed intake as pasture with the remainder of intake as a barley-based concentrate. The proportion of VA in milk fatty acids increased 12% when pasture intake increased from 50 to 65% of total dry matter intake and VA, CLA, and linolenic acid proportions increased 26, 18, and 27%, respectively, as pasture increased from 65 to 80% of dietary intake. In experiment 2, fresh forage was compared to conserved hay (cut from the same pasture the previous summer) to determine the effect on plasma and milk fat VA, CLA, and linolenic acid. Also, the effect of crushed solin seed (a flax cultivar that is high in linoleic acid) supplementation to the fresh forage diet was determined. Fresh forage compared to conserved hay in the diet, increased the proportion of CLA in the plasma very low density lipoproteins (VLDL) fraction by 71% but had no effect on linolenic acid. Supplementation of the fresh forage diet with a linoleic acid source increased VA and CLA in the plasma VLDL fraction 25 and 58% and slightly decreased the proportion of linolenic acid. Fresh forage, compared to conserved hay, increased milk fat VA and CLA proportions by 22 and 15%. Supplementing the fresh forage diet with linoleic acid from crushed solin seed further increased milk fat VA and CLA proportions 41 and 25%. Solin supplementation in a lactation diet is a superior method to increase CLA levels in milk fat than feeding fresh forage alone.

Inflammatory components in endarterectomy lesions: an immunohistological study

The aim of this study was to characterize the immunohistological components of chronic inflammation in endarterectomy lesions. Therefore, in 24 patients endarterectomy specimens were obtained from coronary arteries during CABG surgery (16 from RCA and 8 from LCA) and immunohistologically analyzed using avidin-biotin method (LSAB(R)/AP) with monoclonal antibodies. Macrophages and CD3 lymphocytes were counted under 200x magnification but MHC class II and ICAM-1 adhesion molecules were analyzed semi-quantitatively (scale from 0 to 3+). The mean macrophages density was 47.8+/-9.8 cells per mm2 and mean CD3 lymphocyte density was 1.3+/-0.6 cells per mm2. Lack or weak expression of HLA-DR (0-1+) on macrophages was found in 17 of 24 cases (70.8%). In the remaining seven cases (29.2%) there was a moderate and strong expression (2+ and 3+) of HLA-DR antigens. Similarly, no or weak ICAM-1 expression on macrophages was detected in 19 cases (79.2%). These cells were positively stained for ICAM-1 in only five cases (20.8%). Our data suggest that in advanced primary atherosclerotic lesions chronic inflammation is still present. On the other hand, the small number of activated inflammatory cells and the absence of positively stained endothelium suggests that inflammatory process tends to be burnt-out.

Bovine milk fatty acid profiles produced by feeding diets containing solin, flax and canola

Fatty acid profiles with emphasis on linoleic, linolenic, oleic, and conjugated linoleic acid (CLA) were compared in milk from dairy cows fed diets containing 3.25% supplemental fat and a control diet containing no supplemented fat. The fat was supplied by either whole ground solin, flax, or canola oilseed. Solin (linola) is a new cultivar of flax that contains 28% linoleic acid in the seed, Twelve multiparous Holstein cows were assigned to one of four dietary treatments. The experimental design was a 4 x 4 Latin square with each period consisting of 16 d for adjustment to the diet followed by a 5-d sampling period. Feed intake, milk yield, milk fat yield, and milk fat percentage were not affected by treatment. Adding solin, flax, or canola oilseed to lactation diets produced the highest proportions of linoleic (C18:2), linolenic (C18:3), and oleic (C18:1) acids, respectively, in the lipid fraction of the milk of the cows consuming these diets. The proportions of C6:0 to C16:1 were depressed in the milk fat of cows fed the oilseed diets, compared with the control diet. Increasing the lactation diet levels of C18:2, by using different oilseeds, increased CLA to 1.5% of milk fatty acids. The content of CLA in milk fatty acids, however, did not increase with the solin-supplemented diet compared with the canola-supplemented diet even though the C18:2 level was higher in the former diet.

A congenital defect of the pericardium

Ten patients with congenital defects of the pericardium were treated in Departments of Cardiac Surgery, Silesian School of Medicine in Zabrze and Katowice between 1989 and 1998. There were eight children and two adults, eight males and two females. In each case the pericardial defect was discovered intraoperatively during surgery for congenital heart defect. There were no cases with clinical symptoms that could be clearly related to the defect of the pericardial sac. In the case of a child with a complete absence of the left pericardial wall the heart was significantly rotated contrary to the defect. The final outcome of the congenital heart defect surgery was satisfactory in each case. An abbreviated historical review of the diagnosis and treatment of the pericardial defects is presented with special attention placed on therapeutic management. Surgical correction of pericardial defects is concluded to be justified in patients with clinical symptoms. In most cases pericardial defects are discovered intraoperatively, but when they are large the said defects do not require any treatment.