Search Results (162)

Background: Atrial fibrillation (AF) is a common arrhythmia with a high incidence, and patients with chronic obstructive pulmonary disease (COPD) are at particularly high risk. However, there are currently no tools available for early risk stratification of AF in this population. Objectives: To develop and validate a neural network diagnostic model based on transthoracic echocardiography to address two clinical challenges in patients with COPD: risk stratification for AF; and detection of occult supraventricular arrhythmias (including “micro-AF”) based on 24 h ECG monitoring data. Methods: The study consisted of three consecutive stages: development of a neural network (NN) based on transthoracic echocardiography (TTE) parameters, validation of the model’s predictive ability in patients (n = 311, including 99 with COPD), and assessment of the ability to detect occult atrial arrhythmias (n=207) in patients with COPD. The model architecture consists of a fully connected multilayer perceptron (MLP) with 13 inputs, 4 hidden layers of 130 neurons each, and 2 output neurons. Training was performed on 684 TTE scans (292 without AF, 392 with AF). The echocardiographic parameters were validated on an independent test set (n = 100). Statistical analysis included pairwise and multiple comparisons, logistic regression analysis, and ROC analysis with assessment of the area under the ROC curve (AUC). The median follow-up period for study participants was 18 months. Results: The neural network demonstrated high classification metrics for AF on the test set (AUC = 0.80). A threshold value of the first output layer neuron > 0.75 allowed for the identification of a high-risk subgroup, in which the incidence of AF in patients with COPD was 14.8% versus 0% in the low-risk subgroup (p = 0.0073). Logistic regression models of the relationship between AF development and the neural network output value were statistically significant in both patients with COPD and patients without COPD (p < 0.0001). In patients with COPD without a history of AF, the neural network identified a high-risk group. In this group, 24 h ECG monitoring more frequently recorded episodes of AF, group supraventricular extrasystoles, and the combined endpoint (AF + GSE) compared to the low-risk group (55.32% vs. 17.5%; p < 0.0001). The area under the ROC curve for detecting latent AF in patients with sinus rhythm based on the neural network prediction was 0.93. Conclusions: The developed neural network model, which integrates a set of TTE parameters into a single quantitative measure of the severity of myocardial remodeling, is an effective tool for risk stratification for AF. The model may help identify COPD patients who could benefit from intensified rhythm monitoring; however, external validation is required before clinical implementation. Full article

Background: Migraine is a neurological disorder affecting approximately 15% of the general population, and autonomic nervous system (ANS) dysfunction is a well-characterized feature of the condition. Sympathovagal imbalance during acute migraine attacks has been linked to cardiac electrical instability. This study aimed to evaluate atrial and ventricular myocardial repolarization markers in migraine patients at three serial electrocardiography (ECG) time points. Methods: A prospective observational cross-sectional study was conducted in a tertiary emergency department (ED), enrolling 70 migraine patients and 70 age- and sex-matched healthy controls. Three 12-lead ECGs were obtained per patient: during the migraine attack (within 60 min of ED admission), after analgesic treatment (verbal pain relief or Numeric Rating Scale [NRS] decrease greater than 4 points), and in the pain-free period (at least 24 h after the attack, within 7 days). Measured parameters included P-wave duration, P-wave dispersion, QT interval, QT dispersion, corrected QT (QTc) duration (Bazett formula), QTc dispersion, Tpeak–Tend (Tp-e) interval, Tp-e dispersion, and Tp-e/QTc ratio. ECGs were evaluated by two blinded emergency medicine specialists. Results: All repolarization markers were significantly higher in migraine patients than in controls (p < 0.05 for all). Comparing the first (ictal) with the second (post-treatment) measurements, all markers except P-wave dispersion decreased significantly (p < 0.05). All markers were significantly higher during the attack than in the pain-free period (p < 0.05 for all). Tp-e interval and Tp-e/QTc ratio showed a further significant reduction between the second and third measurements (p = 0.016 and p = 0.004, respectively). P-wave dispersion was significant only for the first-to-second comparison (p = 0.034) and did not differ significantly between the first and third (p = 0.137) or second and third (p = 0.725) measurements. Pulse rate was significantly higher in the migraine group than in controls (p = 0.012). Conclusions: Acute migraine attacks were associated with significant elevation of both atrial and ventricular repolarization markers, with near-normalization during pain-free periods. These findings are consistent with a proposed mechanism of ANS-mediated cardiac electrical instability during acute attacks, although direct confirmation in future studies is required. Clinicians managing acute migraine in the ED should consider ECG monitoring in patients with cardiovascular risk factors. For anesthesiologists and intensivists, the elevated Tp-e and Tp-e/QTc observed ictally indicate that preoperative ECG assessment in migraine patients may be warranted to guide anesthetic planning. Full article

Background: Heart failure (HF) is a complex clinical syndrome that presents significant challenges in diagnosis and treatment. Exploring innovative pathways to better understand the physiopathological mechanisms has led to the concept of cardiac remodeling (CR), which helps elucidate the diversity in clinical manifestations and treatment responses. However, the extent to which CR influences autonomic cardiac dynamics across the circadian cycle remains unclear. Methods: Recordings of 24 h ECG recordings from 86 Control subjects and 86 patients meeting the criteria for cardiac remodeling were analyzed. Heart rate variability (HRV) parameters were estimated using 5 min Blackman–Harris windows per hour. Autonomic influences on cardiac electrical activity were assessed using time-domain, frequency-domain, and nonlinear methods. Circadian parameters (MESOR, amplitude, and acrophase) were derived via Cosinor modeling, and group differences were evaluated while controlling for age, sex, and medication effects. Results: Patients with CR exhibited reduced oscillatory activity in HRV measures compared with Control. MESOR and amplitude were significantly lower in CR patients, who also displayed an advanced-phase phenotype across multiple HRV domains over 24 h. Additionally, CR patients showed decreased complexity and entropy in nonlinear dynamics. Conclusions: Altered circadian rhythmicity of cardiac electrical activity is evidenced in cardiac remodeling by changes in circadian HRV parameters and nonlinear dynamics. Full article

Heart failure (HF) is accompanied by autonomic dysregulation and disrupted physiological rhythms, yet how cardiorespiratory coupling (CRC) reorganizes across the circadian cycle during everyday life remains incompletely characterized. We studied 24 h ambulatory ECG recordings from 88 healthy controls and 75 patients with HF. Cardiac autonomic dynamics were quantified from RR intervals using standard HRV indices and symbolic/entropy descriptors, and circadian organization was assessed with 24 h cosinor modeling. Respiratory timing was derived from ECG-derived respiration (EDR) to obtain breath-to-breath (BB) intervals and the pulse–respiration quotient (PRQ). System-level coupling was evaluated primarily as event-timing coordination using coordigram-based coordination percentages computed at two timing tolerances (ε = 0.1 s and ε = 0.2 s) over 24 h and hour-by-hour, and complemented by entropy-based timing irregularity for RR, BB, PRQ, and RR–BB cross-entropy. Patients with HF exhibited lower global HRV and reduced information content in RR dynamics, together with circadian chronodisruption characterized mainly by weaker rhythmic expression and increased inter-individual phase dispersion. CRC differences depended on both tolerance and time of day. In entropy-based profiles, RR–BB cross-entropy and RR entropy did not show hour-specific differences; instead, group separation was localized to higher early-night ApEn in BB in HF and to consistently higher daytime/early-evening FuzzEn in PRQ in controls. Together, these findings indicate a time-structured remodeling of cardiac autonomic dynamics and CRC in HF, in which autonomic function is compromised, and coupling alterations become most evident when examined at appropriate timing tolerances and with circadian (hour-resolved) resolution. Full article

Electrocardiographic changes resembling myocardial ischemia are rare in gastrointestinal emergencies. In particular, gastric perforation has been reported in association with ST-segment elevation, but not with ST-segment depression mimicking non-ST-segment elevation myocardial infarction (NSTEMI). We report the case of a 60-year-old woman presenting with sudden-onset epigastric pain radiating to the chest. She remained hemodynamically stable throughout her emergency department stay. On admission, the ECG showed diffuse ST-segment depression with ST-segment elevation in aVR. High-sensitivity troponin and inflammatory markers were within normal limits. Coronary angiography revealed no significant coronary stenosis, and left ventriculography demonstrated preserved left ventricular systolic function. Abdominal computed tomography showed abundant pneumoperitoneum, diffuse anterior gastric wall thickening, and moderate intraperitoneal fluid, findings highly suggestive of gastric perforation. The patient underwent laparoscopic gastric repair and abdominal lavage, with an uneventful postoperative recovery. A repeat ECG 24 h after surgery showed complete resolution of the ST-segment abnormalities. To our knowledge, this is the first reported case of gastric perforation presenting with diffuse ST-segment depression and aVR ST-segment elevation. Awareness of this presentation helps to broaden the spectrum of diagnostic possibilities and to plan appropriate diagnostic–therapeutic procedures. Full article

Background and Objectives: The interaction between the brain and heart has become more interesting in the last 20 years. The most common cardiac complications after stroke are myocardial infarction, heart failure, arrhythmias, electrocardiographic disturbances, repolarization disorders, and sudden cardiac death. The prolonged Tpeak–Tend interval is an indicator of the electrical heterogeneity of the myocardium (abnormal repolarization) that causes malignant arrhythmias. We aimed to investigate whether the Tpeak–Tend interval, which reflects the heterogeneity of repolarization, is prolonged in stroke and its relationship with short-term mortality. Materials and Methods: Individuals over the age of 18 who presented with hemorrhagic or ischemic stroke were included in the study. Demographic characteristics, laboratory and imaging findings of the patients were recorded. ECGs were obtained at the time of admission to the hospital and 24 h later. Patients were followed for in-hospital mortality. Results: 89 (82.4%) of the patients had ischemic stroke, 19 (17.6%) had hemorrhagic stroke. It was determined that Tp-eV2 and Tp-eV5 at hospital admission were significantly longer than the 24th hour values. A total of 92.01 (16.3) ms at Tp-eV2 admission, 84.1 (16.3) ms after 24 h (p = 0.003), 91.9 (7.3) msTp-eV5 at admission, and 81.6 (17.8) ms (p = 0.000) after 24 h. In multivariate logistic regression analysis of in-hospital mortality, Tp-eV2 (HR: 0.96 (95% CI 0.93–0.99) p = 0.008) was determined as an independent predictor among cardiovascular parameters. Conclusions: Tp-e intervals were prolonged in both leads V2 and V5 in patients with stroke. Prolongation of lead V2 in the Tp-e interval is an independent indicator of short-term mortality among cardiovascular parameters. Full article

Background/Objectives: Poincaré plot analysis represents a nonlinear approach to heart rate variability (HRV) assessment, but the physiological meaning of several derived parameters remains unclear. This study aimed to evaluate associations between selected Poincaré plot-derived parameters, conventional HRV indices, and cardiovascular autonomic reflex tests in a real-world clinical population. Methods: This observational study included 269 adult patients referred for evaluation of suspected autonomic dysfunction. All participants underwent short-term resting ECG, cardiovascular autonomic reflex testing, and 24 h Holter ECG monitoring. Poincaré plot-derived parameters were analyzed in relation to short- and long-term HRV measures using the Spearman correlation with false discovery rate correction, and group comparisons were performed based on reflex test results. Results: Several Poincaré plot-derived parameters showed strong correlations with long-term HRV indices. VLI and LA were primarily associated with global and long-term autonomic variability, whereas VAI and SA were more closely related to parasympathetic modulation. Associations with short-term HRV were generally weak. Lower values of selected parameters were observed in patients with abnormal parasympathetic reflex tests, while no significant differences were found in relation to orthostatic hypotension. Conclusions: Poincaré plot-derived parameters capture complementary aspects of autonomic regulation beyond conventional HRV indices and may enhance autonomic phenotyping in clinical settings. Full article

A 2-year-old female Labrador Retriever, with a body condition score of 6/9, underwent ovariohysterectomy 24 h prior at another center and was urgently referred for a possible exploratory laparotomy. The dog presented with lethargy, abdominal pain, and a haematoma with active bleeding in the surgical wound, indicating a possible haemoabdomen. An abdominal-Focused Assessment with Sonography for Trauma (A-FAST) revealed fluid in all four quadrants (abdominal fluid score-AFS 4/4) without abdominal distension, corresponding to an effusion with a packed cell volume of 15% and 4 g/dL of protein. Haematological analysis showed a slight decrease in haematocrit (HCT) and red blood cells, with neutrophilia, while the rest of the blood tests were within normal limits. Physical examination parameters were mostly normal, except for cardiac auscultation where tachycardia, irregular rhythm, and pulse deficit were noted, with normal blood pressure. The electrocardiogram (ECG) indicated both monomorphic and polymorphic ventricular tachycardia with isolated episodes of sinus tachycardia. Treatment included the administration of metamizole, methadone, and maintenance fluid therapy, along with compressive abdominal bandaging. Lidocaine and continuous infusion of fentanyl therapy were initiated. The dog’s HCT, platelets, temperature, and blood pressure remained in the normal range. During the first 8 h, both the ECG and A-FAST showed no relevant changes. From the 9th hour onward, there was a predominance of sinus rhythm, the free fluid decreased to AFS 1/4, allowing for the gradual suspension of lidocaine. Tests for Leishmania, Ehrlichia, Anaplasma, Babesia, and Dirofilaria were negative. The evolution remained favorable, and the dog was discharged after 72 h, showing a good outcome in the cardiology follow-up 5 days later. Full article

Background/Objectives: Aortic stenosis is associated with autonomic nervous system (ANS) imbalance, while diabetes mellitus is a major contributor to cardiac autonomic neuropathy. Their coexistence may result in more pronounced autonomic dysfunction not fully captured by conventional assessment. This study aimed to compare ANS function in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR), according to diabetes status. Methods: This cross-sectional study included 74 patients with severe aortic stenosis referred for TAVR, including 21 patients with diabetes mellitus. Autonomic function was evaluated using non-invasive ECG-based analysis, incorporating short-term and 24 h Holter-derived heart rate variability (HRV), nonlinear Poincaré plot indices, and deceleration and acceleration capacity. Ambulatory blood pressure monitoring and standard clinical and echocardiographic assessment were performed. Results: Patients with diabetes mellitus demonstrated significantly lower long-term HRV parameters and reduced nonlinear Poincaré plot indices compared with non-diabetic patients, indicating altered autonomic modulation. Short-term HRV showed similar trends without statistical significance. Echocardiographic severity of aortic stenosis and left ventricular systolic function were comparable between groups. Conclusions: Autonomic dysfunction appears to be more pronounced in patients with severe aortic stenosis and diabetes mellitus, predominantly affecting parasympathetic modulation. ECG-derived autonomic parameters may offer complementary insight into ANS involvement in this population and warrant further investigation. Full article

Background and Objectives: Effective postoperative analgesia is essential for enhanced recovery after bariatric surgery. The erector spinae plane block (ESPB) has emerged as a promising regional anesthesia technique, but its impact on postoperative pain control, opioid requirement, patient and surgeon satisfaction, and stress response in obese patients undergoing sleeve gastrectomy remains unclear. This study aimed to evaluate the effects of bilateral ESPB on postoperative analgesia requirements, pain scores, patient and surgeon satisfaction, hemodynamic stability, postoperative stress response, and perioperative hematologic and biochemical parameters in ASA II–III patients with a body mass index (BMI) > 30 undergoing sleeve gastrectomy. Study design was a prospective, randomized, single-blind clinical trial. Materials and Methods: After obtaining ethics committee approval (Şanlıurfa Harran University Hospital, date: 23 January 2023; decision no: HRÜ/23.02.09) and written/verbal informed consent, 60 patients aged 18–65 years, BMI > 30, ASA II–III scheduled for elective sleeve gastrectomy were included. Patients were randomized into two groups: those receiving bilateral ESPB (Group E, n = 30) and those without ESPB (Group C, n = 30). Demographic characteristics, ASA scores, comorbidities, and surgical duration were recorded. Preoperative venous samples were collected into hemogram (WBC, lymphocyte, neutrophil) and biochemistry tubes (CRP, cortisol, glucose). Standard monitoring (ECG, SpO₂, NIBP) was applied intraoperatively, and vital parameters (HR, MAP) were recorded throughout. Postoperatively, HR, MAP, Numerical Rating Scale (NRS) scores at 0, 2, 4, 8, and 24 h, opioid requirement, patient and surgeon satisfaction (Likert scale), postoperative hemogram and biochemistry values, and side effects or complications were documented. All patients received dexketoprofen as baseline analgesia, with tramadol HCl administered as rescue analgesic. Results: All 60 patients completed the study. There were no statistically significant differences between the groups regarding age, BMI, or surgery duration. Comorbidities were similar between groups. Intraoperative and postoperative HR and MAP values showed no significant differences. Postoperative NRS scores at the 0, 2, 8, and 24 hours were significantly lower in Group E compared with Group C. Both patient and surgeon satisfaction scores were higher in Group E. Rescue analgesic (tramadol HCl) consumption in the postoperative ward was significantly reduced in Group E. Cortisol levels, particularly at the 24th postoperative hour, showed a significantly smaller increase in Group E, suggesting a reduced surgical stress response. No significant differences were found between the groups regarding postoperative side effects or complications. Conclusions: Preoperative bilateral ESPB is an effective component of multimodal analgesia in sleeve gastrectomy. The block significantly reduces postoperative pain intensity, lowers NRS scores, improves patient and surgeon satisfaction, and decreases opioid requirements. Additionally, ESPB appears to attenuate the postoperative stress response, as reflected by smaller increases in cortisol levels. These findings support the routine incorporation of ESPB in perioperative pain management strategies for gastric sleeve surgery. Full article

Background: Rickettsial diseases are endemic in southeastern Mexico, yet their potential subclinical cardiac effects remain poorly understood. Although severe spotted fever and typhus group infections may cause myocarditis and arrhythmias, limited evidence exists regarding cardiac alterations in individuals previously diagnosed with rickettsiosis who later show Rickettsia spp. IgG seropositivity. Methods: This follow-up observational study was conducted at a tertiary referral hospital in the Yucatan Peninsula. From an initial cohort of 390 patients evaluated for suspected rickettsial disease, 284 were confirmed as IgG-positive during follow-up. Among them, 18 adults who were asymptomatic for acute rickettsiosis at reassessment, but reported mild or nonspecific cardiac symptoms, underwent standardized cardiological evaluation. Procedures included a 12-lead electrocardiogram (ECG), transthoracic echocardiography, and 24 h Holter monitoring. All studies were reviewed independently by two blinded cardiologists with senior adjudication. Results: Global systolic function was preserved in all participants. However, subclinical abnormalities were identified, including right ventricular dilation in 16.7%, clinically relevant QTc prolongation in 22.2%, sinus pauses in 11.1%, reduced heart rate variability in 11.1%, atrial flutter in one patient, and complete left bundle branch block in one patient. QTc prolongation was detected exclusively through Holter monitoring. Conclusions: Adults previously diagnosed with rickettsiosis may exhibit subclinical cardiac involvement despite apparent recovery. Holter monitoring appears more sensitive than ECG for identifying electrical disturbances, warranting larger prospective studies. Full article

Background: Persistent inflammation and endothelial dysfunction have been proposed as key mechanisms of post-COVID cardiovascular sequelae and may contribute to atrial fibrillation (AF). We examined whether inflammatory/prothrombotic biomarkers and endothelial function differ between post-COVID patients and controls, and whether baseline inflammation/endothelial dysfunction relates to AF burden at 12 months. Methods: In this single-center, retrospective observational study, 198 outpatients were enrolled: 99 post-COVID patients evaluated 3–6 months after documented SARS-CoV-2 infection (Group 1) and 99 age- and sex-matched controls without prior COVID-19 (Group 2). At baseline (t0), clinical characteristics, inflammatory/prothrombotic biomarkers, brachial artery flow-mediated dilation (FMD), and 24 h Holter ECG were assessed in both groups. Univariable linear regression tested associations between baseline variables and FMD in Group 1. At 12 months (t1), 24 h Holter ECG was repeated in both groups. Quartile analyses were performed according to baseline neutrophil-to-lymphocyte ratio (NLR) to explore AF distribution across inflammatory strata. Results: At baseline, post-COVID patients had higher inflammatory and prothrombotic markers than controls (ESR, CRP, fibrinogen, and D-dimer; all p < 0.0001) and markedly lower FMD (7.72 vs. 13.72; p < 0.0001). In Group 1, FMD was inversely associated with multiple inflammatory/prothrombotic markers (all p < 0.0001), with the strongest association for ESR (R² = 0.6297). Holter-detected AF prevalence at baseline did not differ significantly between groups (25/99 [25.3%] vs. 18/99 [18.2%]). At 12 months, AF prevalence was numerically higher in the post-COVID group (32/99 [32.3%] vs. 21/99 [21.2%]); on two-sided testing, this difference was borderline (p = 0.047) and should be interpreted cautiously. Across increasing baseline NLR quartiles, AF prevalence increased stepwise in both groups (post-COVID: 2/25, 5/25, 10/24, 15/25; controls: 1/25, 3/25, 7/24, 10/25), consistent with the enrichment of AF in higher-inflammatory strata. Conclusions: Post-COVID patients exhibited a persistent inflammatory–prothrombotic profile and pronounced endothelial dysfunction at baseline. At 12 months, AF burden was numerically higher post-COVID, and AF clustered in strata characterized by higher baseline NLR and lower FMD, consistent with an inflammation–endothelial dysfunction axis associated with subsequent AF burden. Prospective studies with standardized rhythm monitoring and comprehensive multivariable adjustment are warranted. Full article

Background and Objectives: There is a well-established correlation between premature ventricular contractions (PVCs) and atrial fibrillation (AF), with a higher burden of PVCs increasing the likelihood of new-onset AF. This study aims to investigate the impact of heart rate variability (HRV) on the onset of AF in patients with moderate to high burdens of PVCs, as observed through 24 h ambulatory electrocardiogram (ECG) analysis. Materials and Methods: Our study was a retrospective analysis involving 187 patients at a single tertiary center. We analyzed PVC counts from 24 h ECG recordings, categorizing the patients into groups based on whether they developed AF or not. Additionally, we developed a nomogram to estimate the risk of AF development in these patients. Results: A new-onset AF was detected in 16% of the cohort. Analysis of 24 h ambulatory ECG data revealed statistically significant increases in the SDNN index, RMSSD, PNN50, total power (TP), and low-frequency (LF) values in AF patients. To estimate the risk of AF, a risk prediction nomogram was created using high-frequency (HF), LF, SDNN index, and PNN50. Among these variables, PNN50 was identified as the strongest predictor in the multivariable model. Additionally, a decision curve analysis demonstrated that the nomogram offers a net clinical benefit for detecting AF in patients when the baseline threshold risk exceeds 15%. Conclusions: Our study found that among patients with AF who had a moderate to high burden of PVCs using 24 h ambulatory ECGs, several HRV parameters were elevated. This increased autonomic instability may play a role in the development and persistence of AF episodes. Full article

Background: Device-detected subclinical atrial fibrillation (SCAF) and atrial high-rate episodes (AHRE) are increasingly recognized in patients with cardiac implantable electronic devices and through long-term rhythm monitoring. Although often asymptomatic, these episodes are associated with a higher risk of clinical atrial fibrillation (AF), stroke, and heart failure. Aims: This narrative review summarizes clinical, electrocardiographic, echocardiographic, and circulating biomarkers associated with the development and progression of device-detected SCAF/AHRE. Methods: We performed a comprehensive search of PubMed, Embase, and Scopus using combinations of the terms “subclinical atrial fibrillation”, “atrial high-rate episodes”, “device-detected AF”, “predictive factors”, “P-wave morphology”, “echocardiographic parameters”, “left atrial strain”, and “biological markers”. We included English-language-only studies of patients with cardiac implantable electronic devices or long-term monitoring and reporting incident SCAF/AHRE or AF as outcomes, published in the last 10 years. Results: Older age, high body mass index, heart failure, obstructive sleep apnea, and C₂HEST score are consistently associated with SCAF. On-surface electrocardiogram (ECG) and device electrograms, prolonged and dispersed P-wave indices, low atrial sensing amplitude, and specific pacing configurations, particularly right ventricular apical pacing with wide QRS, predict incident and longer-lasting AHRE. Echocardiographic markers of atrial cardiomyopathy, including increased left atrial volume and impaired atrial strain, together with indices of left ventricular diastolic dysfunction, further refine risk. Among circulating biomarkers, galectin-3 and high-sensitivity C-reactive protein show the most reproducible associations with incident AHRE. Conclusions: A multiparametric approach combining clinical profile, ECG features, advanced echocardiography, and selected biomarkers may improve identification of patients at risk for device-detected SCAF. Further prospective studies are needed to define risk thresholds that justify intensified rhythm surveillance and early initiation of anticoagulation or rhythm control strategies, especially in AHRE shorter than 24 h. Full article

Background/Objectives: Non-dilated left ventricular cardiomyopathy (NDLVC) is a recently defined clinical entity associated with increased risk of ventricular arrhythmias (VA) and sudden cardiac death (SCD), despite preserved LV geometry. The role and temporal variability of noninvasive electrocardiographic (ECG) risk markers in this population remain insufficiently characterized. To assess the temporal variability of ECG-derived risk markers in patients with NDLVC and explore their association with major adverse cardiac events, including heart failure (HF) and VA hospitalization. Methods: We prospectively studied 55 patients with NDLVC who underwent cardiac magnetic resonance imaging and serial 24 h Holter monitoring, signal-averaged ECG, and standard 12-lead ECG over a one-year period. Patients were followed up for 39.5 ± 8.6 months. Nine ECG-based risk markers were analyzed, including premature ventricular contraction (PVC) burden, non-sustained ventricular tachycardia (NSVT) occurrence, its maximum rate and maximum beats, mean QTc interval, standard deviation of NN intervals (SDNN), deceleration capacity (DC), heart rate turbulence onset and slope (TO/TS), T-wave alternans (TWA), and late potentials. Clinical outcomes were HF and VA hospitalization. Logistic regression was used to evaluate associations between changes in ECG parameters and outcomes. Results: A change (from positive to negative and vice versa) in at least one ECG parameter was detected in 67.3% of patients, with the highest variability observed in TWA (34.5%), NSVT (23.6%), and PVC burden (23.6%). Despite this variability, only SDNN was significantly associated with increased risk of VA hospitalization during follow-up (OR = 0.98, 95% CI: 0.97–0.99, p = 0.006). No ECG changes were associated with HF hospitalization. Conclusions: Patients with NDLVC exhibit substantial temporal variability in noninvasive ECG risk markers. While most changes do not correlate with clinical events, an inverse association was found between SDNN and VA risk. These findings support the ongoing evaluation and the necessity to identify more effective risk stratification markers in this subgroup of patients. Full article