Publications by authors named "Coromilas J"
Article Synopsis
- Sinus rhythm activation time is a key indicator for evaluating the substrate of heart tissue following an infarct, particularly in the context of ventricular tachycardia (VT).
- A study involving dogs post-infarction revealed that analyzing sinus rhythm and VT electrograms can reveal patterns that predict VT inducibility.
- The findings suggest that the sinus rhythm activation signature can help differentiate between conditions that support reentrant VT and those that do not, which is important for targeting treatment locations within the heart.
Correlation relationships of the reentrant ventricular tachycardia circuit.
Comput Methods Programs Biomed
November 2023
Article Synopsis
- A study was conducted using 19 canine experiments to examine how reentrant ventricular tachycardia (VT) is initiated and sustained, focusing on mapping heart circuitry post-infarction.
- Findings revealed a correlation between the extrastimulus interval used to induce VT and the VT cycle length, suggesting that a specific boundary length (LIB) within the heart's circuitry plays a crucial role in VT dynamics.
- The research concluded that while shorter LIBs are closely related to VT cycle length, other circuit parameters like isthmus width and angle showed less relevance, potentially due to changes in the heart tissue's structure after an infarct.
Article Synopsis
- The study investigates how mapping electrical activity during sinus rhythm can help identify areas of disrupted conduction in hearts affected by ischemic re-entrant ventricular tachycardia.
- Researchers constructed activation maps from electrograms of canines with postinfarction hearts, focusing on regions known as isthmus lateral boundaries (ILB).
- Results show significant differences in activation times at ILB locations compared to other circuit parts, suggesting that these areas may be linked to long-lasting changes in electrical properties due to heart tissue damage.
Article Synopsis
- A 71-year-old man with ongoing atrial fibrillation and a permanent dual chamber pacemaker experienced shortness of breath, fatigue, and a cough.
- An electrocardiogram showed both paced and native QRS complexes along with irregular atrial activity.
- The case highlights a rare cause of atrioventricular dyssynchrony in this patient.
The goal of this study was to identify how often 2 independent centers defibrillated patients within the American Heart Association recommended 2-minute time interval following ventricular fibrillation/ventricular tachycardia arrest. A retrospective chart review revealed significant delays in defibrillation. Simulation sessions and modules were implemented to train nursing staff in a single nursing unit at a Philadelphia teaching hospital.
View Article and Find Full Text PDFArticle Synopsis
- - The study evaluated national practices among implanters of cardiovascular implantable devices (CIEDs) regarding antibiotic use for infection prevention, finding that 97% routinely use systemic antibiotics before surgery.
- - A significant number of implanters, about two-thirds, continue antibiotics after the procedure, with 83% using antibiotics in saline for wound irrigation and 55% regularly employing antibiotic-eluting envelopes (ENVELOPE) for select patients.
- - Results indicated considerable variation in antibiotic practices and highlighted a need for better adherence to guidelines and further research to optimize the use of ENVELOPE in clinical settings.
Article Synopsis
- The study aimed to understand the effects of delayed high-degree atrioventricular block (HAVB) or complete heart block (CHB) after patients underwent transcatheter aortic valve replacement (TAVR), using continuous monitoring.
- A total of 459 patients were monitored for 14 days post-procedure, revealing that 4.6% experienced delayed HAVB or CHB, particularly those with existing right bundle branch block (RBBB) or new ECG disturbances.
- The findings suggest that while these conditions were relatively uncommon, they occurred more frequently in high-risk groups, highlighting the need for tailored monitoring and potentially longer hospital stays for at-risk patients.
Article Synopsis
- The study investigates the effectiveness of ambulatory cardiac monitoring (ACM) in identifying delayed advanced conduction abnormalities (DACA) and 30-day mortality in patients who underwent Transcatheter Aortic Valve Replacement (TAVR).
- The research monitored 248 TAVR patients post-discharge using ACM for 14 days, finding a 7% incidence of DACA, with no deaths and an 8.3% readmission rate within 30 days.
- Patients with normal ECGs saw no DACA events, highlighting the potential value of ACM in monitoring high-risk groups after TAVR surgery.*
Article Synopsis
- Catheter ablation for treating postinfarction reentrant ventricular tachycardia (VT) is gaining traction due to better electroanatomic mapping technologies and the need for noninvasive radioablation methods.
- * Recent studies indicate that there are shared electroanatomic characteristics among VT circuits, which could enhance the accuracy of mapping techniques and help direct treatment.
- * Understanding these VT circuit properties can improve our knowledge of how VT starts and persists, leading to more precise targets for catheter ablation.
[Figure: see text].
View Article and Find Full Text PDFThe Rapid Prediction of Focal Wavefront Origins: Integration With a 3-Dimensional Mapping System.
JACC Clin Electrophysiol
November 2020
Article Synopsis
- - This study developed an algorithm that predicts the origin of focal arrhythmias using only two pairs of data points, aiming to improve the efficiency of ablation procedures.
- - The algorithm was tested with data from patients who had successful ablations, and it achieved a high predictive accuracy rate, correctly calculating the origin in 93.9% of attempts within a distance of about 5.7 mm.
- - The results suggest that this new predictive method could enhance the 3D mapping of focal wavefronts during arrhythmia treatment, potentially making procedures faster and more effective.
Article Synopsis
- - The study investigated the accuracy of lead aVR ST-segment elevation (STEaVR) in diagnosing left main or triple vessel disease (LM/3VD) in patients experiencing acute coronary syndrome (ACS).
- - A meta-analysis of 14 studies revealed that STEaVR has a pooled sensitivity of 0.40 and specificity of 0.82 for diagnosing LM/3VD, indicating that while it can be reliable, it is more effective at ruling out rather than confirming these conditions.
- - Conclusively, STEaVR is shown to have high specificity for both LM and 3VD, suggesting it could be a useful tool in ACS evaluations, despite moderate sensitivity.
Article Synopsis
- The study aimed to validate how accurately reentrant circuit isthmus locations can be predicted without inducing ventricular tachycardia (VT) by analyzing sinus rhythm activation in dogs after a heart attack.
- Using computer-aided methods on data collected from 21 experiments, the researchers measured activation patterns in the heart to identify areas where electrical signals are blocked and determine the isthmus's location.
- Results showed that activation along the isthmus was uniform and slow near the exit but less uniform and faster at the entrance, suggesting that specific mapping techniques could help prevent VT by targeting these areas.
Surgical and endoscopic management of a pericardioesophageal fistula after radiofrequency pulmonary vein isolation.
Pacing Clin Electrophysiol
November 2020
Article Synopsis
- The text discusses the serious complication of atrioesophageal fistula (AEF) that can arise from pulmonary vein isolation (PVI), emphasizing that while it's rare, surgical closure is more effective than stenting.
- A case study is presented involving a 71-year-old man who developed a pericardioesophageal fistula (PEF) following PVI, leading to complications including bacteremia and eventually death.
- The conclusion highlights that while AEF management strategies are known, there is a lack of consensus on treating PEF, and the case demonstrates the shortcomings of using esophageal stenting for this condition.
Article Synopsis
- Mitral regurgitation (MR) is often found in patients with severe aortic stenosis (AS), but its specific impact on mortality after transcatheter aortic valve implantation (TAVI) is unclear.
- A systematic review and meta-analysis of 17 studies involving over 20,000 patients revealed that while MR patients had higher initial mortality rates and more comorbidities, many studies showed no significant association between MR and mortality after adjusting for other risk factors.
- The findings suggest that although MR is common in TAVI patients and risk factors are more pronounced, most patients experience an improvement in MR severity post-procedure and adjusted mortality risks do not show a clear correlation.
Article Synopsis
- Pulmonary vein isolation (PVI) effectively reduces excitability in many pulmonary veins during treatment for atrial fibrillation, but the underlying mechanism is not fully understood.
- *In a study of 67 patients, measures like capture threshold and effective refractory period (ERP) were evaluated before and after PVI, revealing significant increases in excitable veins while non-excitable veins showed transient re-excitability with adenosine.
- *The findings suggest that PVI leads to changes in the resting membrane potential of pulmonary vein tissues, highlighting the importance of assessing re-excitability to confirm effective isolation during procedures.*
Irrigated vs. Non-irrigated Catheters in the Ablation of Accessory Pathways.
J Cardiovasc Transl Res
August 2020
Article Synopsis
- There is limited data comparing irrigated catheters to non-irrigated catheters for ablating accessory pathways in adults; this study analyzes 69 cases from 2010 to 2017.
- The study involved mostly middle-aged male patients, with a majority of the accessory pathways located on the left side and a significant number being concealed.
- Results showed a higher success rate for irrigated catheters (94.4%) compared to non-irrigated ones (73.3%), indicating that irrigated catheters are more effective in ablation procedures.
Article Synopsis
- A novel predictive method for identifying the origin of focal arrhythmia wavefronts uses conduction velocity, timing differences, and distance measurements to create curves for electroanatomic mapping.
- A retrospective study involving 12 patients demonstrated the feasibility of this method, successfully generating and analyzing 24 prediction curves.
- The results showed that the average distance from the intersection of these curves to the wavefront origin was approximately 9.2 mm, highlighting the method's potential for improving arrhythmia treatment strategies.
Source-Sink Mismatch Causing Functional Conduction Block in Re-Entrant Ventricular Tachycardia.
JACC Clin Electrophysiol
January 2018
Article Synopsis
- Ventricular tachycardia (VT) is a dangerous heart rhythm issue that is often difficult to treat, highlighting the need for better models to guide treatment, particularly catheter ablation.
- The review focuses on the electrical activity and the relationships between mapping techniques that reveal how changes in heart tissue thickness can lead to re-entrant circuits in VT.
- It suggests that areas with significant differences in infarct zone thickness contribute to the formation of re-entry circuits, while regions with less change act as pathways for these circuits, and the model could apply to other heart conditions involving tissue changes.
Article Synopsis
- * Among the 225 patients who underwent coronary angiography, 47% were found to have significant coronary artery disease (CAD), though noninvasive nuclear stress tests often missed detecting it, showing low predictive values.
- * The study concluded that targeted evaluations can identify patients at high risk for CAD, and that revascularization procedures can improve survival rates for both those awaiting transplants and those who receive one.
Article Synopsis
- This study explores how mid-myocardial reentrant circuits trigger and sustain arrhythmias, focusing on the role of anatomical structures in the heart.
- It develops a model analyzing activation wavefronts in post-infarction areas, examining arrhythmogenic configurations of viable tissue slabs and myocardium strands.
- Findings indicate that specific dimensions and arrangements of these structures (50-600µm thick) influence electrical conduction and block during premature stimulation, impacting the development of reentrant ventricular tachycardia.
Article Synopsis
- Premature stimulation of the infarct border zone can create a unidirectional block line (UBL) that contributes to double-loop reentrant ventricular tachycardia (VT) characterized by a central isthmus with distinct entrance, center, and exit points.
- A quantitative model was developed to explain how changes in border zone thickness from thin to thick result in wavefront curvature and conduction block, with tests conducted on postinfarction canines indicating a relationship between premature stimulation and reentrant VT.
- Results showed that the UBL matched the isthmus boundaries, confirming model predictions on the critical timing and placement of stimuli needed to trigger VT and demonstrating corresponding wavefront behaviors during both premature stimulation and reentrant cycles.*