Inferior Myocardial Infarction Research Articles

Coronary artery dominance in cases with IWMI

Background: Acute coronary syndrome is one of the most common life-threatening emergency and one of the leading causes of sudden death. If diagnosed in time, the patient can be saved. Angiography is the gold standard and helps in identifying the affected vessel. Aims and objective: To see the frequency of coronary artery dominance in cases presenting with inferior wall myocardial infarction. Material and Methods: This cross sectional observational study was done in the emergency department of Punjab Institute of Cardiology, Lahore from March to August 2017. All the patients between 18-60 years of age, both genders, diagnosed with IWMI and had been given thrombolytic therapy within 24 hours of MI were included in this study. Those patients having history of heart failure as determined by the past medical record, patients with renal failure (serum creatinine on admission 1.1 mg/dL), patients with a history of rheumatic heart disease, hypertension 5 years, uncontrolled diabetes (determined by HbA1C 7%), patients having history of previous myocardial infarction or concomitant involvement of other coronary artery areas like an anterior wall or septal wall and those were excluded from this study who did not give informed consent. Results: 227 patients enrolled in this study. Mean age of the patients was 45.07±8.17 years. Males were 51.98% (n=118) and females were 48.02% (n=109) of our study population. Mean BMI was 26.13 ± 3.29. The dominant left circumflex artery (LCX) was found in 25.55% of subjects Right Coronary Artery (RCA) was found to be dominant in 74.45% of our subjects. Conclusion: Presentation of IWMI with RCA as the dominant artery is three times more common as compared to LCx in our local population.

1112 DOUBLE RUPTURE OF INTERVENTRICULAR SEPTUM AFTER MYOCARDIAL INFARCTION

Abstract Ventricular septal rupture (VSR) is a mechanical complication of acute myocardial infarction (MI). VSR and early surgical repair is associated with a high mortality rate and suboptimal results with frequent postoperative residual shunt. Rapid diagnosis and proper management are critical. We present the case of a 73-year-old patient who came to our Emercency Room (ER) reporting oppressive chest pain and profuse sweating . The physical examination showed a 4/6 L rude holosystolic murmur in right parasternal location. Electrocardiogram (ECG) showed inferior MI. Hematochemicals tests detected an increase of myocardial necrosis markers. Two-dimensional and three-dimensional transthoracic echocardiography (TTE) showed normal-sized left ventricle with akinesia of inferior and posterolateral walls and akinesia of posterior basal septum with ventricular septal rupture at this level. Coronary angiography showed total occlusion in mid right coronary artery (RCA). An intra-aortic balloon pump (IABP) was inserted to promote hemodynamic stability of the patient and as a bridge. Afterload was reduced using vasodilatators. A preoperative transesophageal echocardiography (TOE) showed the presence of an additional septal rupture into middle posterior interventricular septum. The role of echocardiographic assessment in VSR, therapeutic management, IABP use and timing of surgery are discussed.

161 ABLATION OF EPICARDIAL VENTRICULAR TACHYCARDIA ORIGINATING IN THE AREA OF PERICARDIAL ADHESIONS INDUCED BY STEREOTACTIC RADIOABLATION IN A PATIENT WITH ISCHEMIC CARDIOMYOPATHY

Abstract This is the case of a 64-year-old male patient with prior inferior wall myocardial infarction, wearing a cardiac resynchronization therapy defibrillator and suffering from recurrent ventricular tachycardia (VT). The patient had undergone a transitory successful endocardial radiofrequency catheter ablation (RFCA) in 2013 and a stereotactic ablative body radiotherapy (SABR) in 2021, targeting the VT originating in the inferior wall myocardial scar. The patient was referred to our institution due to recurrent highly symptomatic slow-VT. A coronary angiography ruled out coronary artery disease (CAD) progression and a RFCA was rescheduled. Given the suspected epicardial origin of VT based on a 12-lead ECG, the decision was made to perform a combined epi-endocardial ablation. SABR-induced pericardial adhesions prevented posterior pericardial access, thus requiring an anterior access approach (Figure 1, Panel A, yellow star). Following epicardial and endocardial electroanatomic mapping (EAM), VT ablation relied on a substrate-based approach. Local abnormal ventricular activities (LAVAs), detected both in the accessible epicardial inferior wall of the left ventricle and at the opposite endocardial site, were eliminated by radiofrequency (RF) current. Upon completion of endocardial ablation, ventricular pacing induced hemodynamically unstable VT, exiting from the epicardial region corresponding to the SABR-induced pericardial adhesions. Mechanical adhesiolysis, using the elbow of the open-irrigated ablation catheter, was performed to disrupt SABR-induced pericardial adhesions in the inferior wall. The epicardial EAM performed with the open-irrigated catheter recorded LAVAs in the infero-posterior wall of the left ventricle, corresponding to the SABR-disrupted pericardial adhesions. A RF current was delivered, targeting LAVAs at this site (Figure 1, Panel B: the central green dot corresponds to the area of disrupted pericardial adhesions). At the end of the procedure, no sustained VT was induced by programmed ventricular stimulation. Conclusion SABR constitutes a novel and promising non-invasive radioablative treatment of VT, potentially associated with cardiac toxicity. To our knowledge, this is the first reported case of combined epicardial and endocardial RFCA of recurrent VT after SABR. Based on the first RFCA report and exclusion of CAD progression, we hypothesized that SABR might have favoured progression of the inferior low voltage area. With this case report, we would like to demonstrate that even if pericardial adhesions could be a consequence of SABR, gentle catheter-driven manoeuvres can be enough to disrupt the adhesions and to achieve full EAM. Further research is mandatory to shed light on SABR's long-term arrhythmogenic role.

Impact of percutaneous coronary intervention in right coronary artery on right ventricular function in patients with acute myocardial infarction.

Background: Right ventricular (RV) dysfunction is a potent predictor of mortality and morbidity following acute myocardial infarction (AMI). Despite the fact that elective percutaneous coronary intervention (PCI) has significantly decreased myocardial damage to the left ventricle, there is a lack of information regarding the effect of PCI on RV function. Aim: This study aimed to examine the effect of right coronary artery (RCA) revascularization on the systolic and diastolic functions of the right ventricle following acute inferior wall myocardial infarction. Methods: Fifty-nine patients diagnosed with acute inferior wall myocardial infarction after RCA revascularization were prospectively investigated between April 2018 and January 2020. The patients underwent 2D echocardiography. RV systolic and diastolic functions were reported before and after the PCI procedure and compared using echocardiographic RV systolic and diastolic parameters. Results: After PCI, echocardiographic RV systolic and diastolic functions significantly improved in the proximal and mid RCA in terms of TAPSE, RVFAC, and E/A. Significant improvement was found in the mid RCA in terms of S' velocity (p=0.008) and in the proximal RCA in terms of E/e' (p=0.021). Overall echocardiographic systolic and diastolic parameters in patients with RV dysfunction following PCI were improved [TAPSE (37.29% vs. 81.82%), S' velocity (37.29% vs. 68.18%), RVFAC (33.90% vs. 90.00%), and E/A (33.90% vs. 75.00%)]. Conclusion: Our findings revealed that patients with RV dysfunction showed remarkable improvement after RCA revascularization. Hence, in future cases, RCA revascularization may become an appropriate treatment alternative for the recovery of patients with RV dysfunction.

Predicting mortality using prognostic scores and electrocardiographic parameters in ST-elevation myocardial infarction patients undergoing thrombolysis

Background: The short- and long-term outcomes of thrombolysis has been predicted by various scores and models based on the electrocardiogram. This study aimed to compare various mortality predictors in ST-elevation myocardial infarction (STEMI) patients undergoing thrombolysis. Methods: A prospective, case-control, single-center study was performed at MGM Hospital, Warangal, India, between November 2019 and November 2021. A total of 100 STEMI patients were enrolled, out of which 50 were controls (patients who survived after seven days of thrombolysis) and 50 were cases (patients who died after seven days of thrombolysis). Aldrich score, TIMI risk index (TRI), Sclarovsky-Birnbaum Ischemia Grading (SB-IG) algorithm, presence of Q waves, total ST-segment deviation, and the number of leads with ST-segment elevation (STE) in anterior wall MI (AWMI) were calculated. Results: The mean age of the case group was 55.3 ± 11.6 years, and that of the control group was 55.5 ± 10.1 years. Males comprised 46.0% and 66.0% of the case and control groups. The c-statistic of TRI was found to be the highest (c = 0.68; P = 0.001), followed by the SB-IG algorithm (c = 0.58; P = 0.021), the sum of R waves in AWMI (c = 0.5; P = 0.019), the number of leads with STE in AWMI (c = 0.47; P = 0.778), total ST-segment deviation (c = 0.47; P = 0.552), Aldrich score for AWMI (c = 0.43; P = 0.590), presence of Q waves (c = 0.40; P = 0.676), and Aldrich score for inferior wall MI (c = 0.32; P = 0.071). Conclusion: TRI and SB-IG algorithms had moderate accuracy in predicting seven-day mortality in STEMI patients undergoing thrombolysis. Other scores and parameters viz. Aldrich score, presence of Q waves, total ST-segment deviation, and the number of leads with STE in AWMI had very poor accuracy in predicting in-hospital outcomes. More extensive studies with longer durations are required to validate our findings.

Effective Following: A Counterpart to Leadership

Effective Following: A Counterpart to Leadership

Assessment of right atrial function in inferior wall AMI

Background: Approximately 30–50% of patients with inferior infarction have some involvement of the right ventricle. The right ventricular (RV) infarction almost invariably develops in association with a large infarction of the adjacent septum and inferior 0 walls, but isolated infarction of the right ventricle is seen in just 3–5% of autopsy-proven cases of MI. This study is designed to assess the right atrial (RA) functions in inferior wall acute myocardial infarction (AMI) (IWMI) echocardiographically and to compare it with patients who do not have history of ischemic heart disease (IHD) but having risk factors for IHD. Aims and Objectives: The aims of this study were to study the patients presenting with Inferior wall MI IWMI for RA function. Materials and Methods: Patients admitted in the Cardiology ward of R G Kar Medical College and Hospital with IWMI from March 2020 to March 2022 were included in the study. Results: Average Measurement of RA volume index (RAVI) and RA Pressure (RAP) was highest among patients with IWMI+RV myocardial infarction (RVMI). Out of 100 IWMI patients, 33 had high RAVI and RAP and out of 100 non-IHD patients none had high RAVI. Conclusion: In our study, there was no statistically significant difference in average RAVI and RAP in patients presenting with IWMI and in patients with risk factors for myocardial infarction but without AMI. However, patients presented with IWMI+RVMI showed statistically significant increased RAVI and RAP as compared to inferior wall AMI only.

Outcome of Primary Percutaneous Coronary Intervention Among Patients of Complete Atrioventricular Block with Acute Inferior St-Elevation Myocardial Infarction

Aim: To assess the outcomes of primary percutaneous coronary intervention among patients of complete atrioventricular block with acute inferior ST-elevation myocardial infarction Methods: We conducted an observational study of patients with CAVB and STEMI who underwent Primary PCI at interventional cardiology department, national institute of cardiovascular diseases Karachi during the period from January 1, 2022 to July 31, 2022. The primary outcomes were in-hospital mortality and CAVB resolution. Results: A total of 100 patients were included in the study. The mean age was 60.63±5.63 years, and 61% were male. The median door-to-balloon time was 89.96±17.97 minutes. In hospital mortality rate was 4%. CAVB was resolved in 93%. Conclusion: For patients with CAVB and STEMI, Primary PCI is a safe and successful treatment with a low rate of in-hospital mortality. These findings support the use of primary PCI in this patient population. Keyword: Primary PCI, CAVB, STEMI

Abstract 12259: Recurrent Coronary Artery Dissection in Patient With Systemic Medium-Sized Vessel Vasculitis

Introduction: Universal definition of myocardial infarction (MI) categorizes spontaneous coronary artery dissection (SCAD) as Type 2 ischemia from non-atherothrombotic obstruction. SCAD is rare but growing evidence suggests it is more common than previously understood. Overlap in clinical presentation with Type 1 MI makes invasive coronary angiography (ICA) the gold standard for diagnosis. Here we present a patient with polyarteritis nodosa (PAN) and the sequelae of coronary artery aneurysms and dissections visualized by ICA and further characterized by noninvasive coronary computed tomography angiography (CCTA). Case Report: A 37-year-old man with smoking and hypertension history presented with acute chest pain that felt similar to when he was diagnosed with SCAD of the first diagonal branch one year prior by ICA. Workup then included elevated inflammatory markers and further imaging demonstrating ectatic and beaded-appearing major intra-abdominal and vertebral arteries consistent with PAN. He completed outpatient cyclophosphamide and continued on chronic oral steroids.The catheterization lab was activated on this presentation for ST segment elevations on initial ECG concerning for an inferior MI. Here the distal branches of the right coronary artery (RCA) had new aneurysms and long stenoses with severe luminal narrowing and intramural hematoma consistent with Type 2 SCAD. The culprit lesions had normal TIMI grade 3 flow so were not revascularized. CCTA further characterized the filling defect and RCA false lumen as Type 1 SCAD. Echocardiogram demonstrated a new wall motion dysfunction in correlative distribution. He was optimized on medical therapy including continued dual antiplatelet agents and steroids. Discussion: This patient’s case lends itself to the hypothesis that his PAN manifested ectatic changes to the coronary vasculature from inflammation that predisposed him to recurrent dissection. Therefore, it is reasonable to initiate a vasculitis workup following discovery of coronary artery ectasia and/or dissection. CCTA may even be an effective tool for diagnosis and surveillance of such disease in the right patient and as a means to avoid invasive testing risks.

Abstract 12152: Recurrent Cerebrovascular Accidents Following Myocardial Infarction With Mechanical Rupture

Background: Mechanical complications of myocardial infarction (MI), including ventriculoseptal ruptures (VSR) and pseudoaneurysms, are potentially life-threatening events but are less common in the era of timely primary percutaneous coronary interventions. Rare case reports describe MI complicated by VSR requiring repair, with delayed left ventricular (LV) pseudoaneurysm formation from the site of VSR repair. We present an atypical manifestation of one such case. Case Presentation: A 55-year-old male was admitted with late presentation inferior MI complicated by inferior VSR, requiring extracorporeal membrane oxygenation and surgical repair. Five months later, he was admitted with left upper extremity weakness and sensory loss. Brain imaging revealed an acute infarct of the precentral gyrus and subacute punctate infarcts of the centrum ovale. He was referred for cardiac magnetic resonance imaging, which revealed a large 6.8x4.9 cm inferior LV pseudoaneurysm containing a large thrombus (Figure 1). He underwent urgent surgery revealing a left ventricular inferior wall defect (Figure 2) and pseudoaneurysm with large mural thrombus. The pseudoaneurysm was successfully repaired via Dacron patch placement and thrombus evacuated. Conclusion: Although less common in the modern era, mechanical complications are possible after severe MI. Clinicians should be aware of the potential for atypical manifestations of these complications, including cardioembolic events that can arise within large pseudoaneurysms.

Point-of-Care Ultrasound Diagnosis of Ventricular Septal Rupture Post Myocardial Infarction: A Case Report

BackgroundVentricular septal rupture (VSR) is a rare but life-threatening complication of ST-elevation myocardial infarction. Point-of-care ultrasound (POCUS) is a rapid, noninvasive imaging modality that is easily accessible and highly effective in diagnosing VSR in the emergency department (ED) setting. Case ReportA 73-year-old man with a history of type II diabetes mellitus and hypertension presented with complaints of intermittent chest pain for 48 h that had since become constant, associated with diaphoresis and shortness of breath. Physical examination was notable for shock and a new, grade V/VI systolic murmur. An electrocardiogram showed evidence of an inferior ST-elevation myocardial infarction (MI) with associated Q waves. POCUS revealed a large ventricular septal rupture with new ventricular septal defect and associated left-to-right shunting. Why Should an Emergency Physician Be Aware of This?POCUS in the ED setting is an effective and rapid tool for elucidating the etiology of various shock states. Emergency physicians should be aware of this particular case, as POCUS may help identify MI-related complications, including post-myocardial infarction VSR, that may necessitate surgical intervention as opposed to coronary reperfusion procedures.

Abstract 10966: Autoimmune Limbic Encephalitis Mimicking Inferior Myocardial Infarction on ECG

Case Presentation: A 64 year-old man was brought to the emergency department (ED) after being found down, awake, but unresponsive by family. In the ED, he denied chest pain and shortness of breath. His past medical history included coronary artery disease status-post coronary artery bypass grafting, heart failure with reduced ejection fraction, and paroxysmal atrial fibrillation. On physical exam, he was hemodynamically stable, oriented to self and place with no other significant neurological findings. The field and ED electrocardiograms (ECGs) (Figure 1) were consistent with an acute inferior ST elevation myocardial infarction (STEMI). The patient underwent emergent coronary angiography via left heart catheterization which showed no acute lesions requiring intervention. Initial pertinent lab work included a peak troponin-I of 0.095 ng/mL and serum sodium of 126 mmol/L. Collateral information revealed that the patient has progressive memory loss and intermittent episodes of hand tremors with non-purposeful eye movements. He also had a witnessed faciobrachial dystonic seizure, which is pathognomonic for Leucine-rich, Glioma Inactivated-1 (LGI-1) autoimmune encephalitis. Serum and CSF analyses were positive for LGI-1 IgG antibodies, confirming the diagnosis. The patient was treated with high-dose steroids, IVIG, and valproic acid with improvement in seizure activity and cognitive status, and discharged on prednisone and levetiracetam. Discussion: Per review of the current literature, central nervous system pathology may induce sympathetic overactivity causing transient myocardial injury, referred to as neurogenic stunned myocardium. This can manifest as left ventricular dysfunction, myocardial injury, and/or ECG changes consistent with myocardial infarction. This case presentation highlights an example of a seizure leading to neurogenic stunned myocardium with an ECG showing an acute inferior STEMI.

Abstract 10162: Acquired Hemophilia A and STEMI: A Management Dilemma

Introduction: Thrombotic events are a rare complication of recombinant activated factor VII (rFVIIa) therapy in patients with hemophilia (PWH). We present the case of a patient who developed ST-segment elevation myocardial infarction while receiving rFVIIa replacement therapy for acquired hemophilia A. Case Presentation: A 71-year-old male with non-invasive right ureteral urothelial carcinoma, hypertension, type 2 diabetes mellitus, hyperlipidemia, and non-obstructive coronary artery disease presented for elective robotic-assisted right distal ureterectomy and ureteral reimplantation. He had persistent hematuria after the procedure. Subsequent evaluation for coagulopathy found acquired FVIII deficiency. He received FVIII replacement therapy but failed to respond due to high levels of FVIII inhibitor. His coagulopathy partially improved after treatment with rFVIIa. Unfortunately, the patient developed ST changes on telemetry. 12 lead ECG showed ST elevations in leads II, III, and aVF. Echocardiogram showed hypokinesis of the inferior wall and preserved ejection fraction. A diagnosis of inferior ST segment elevation MI was made; fortunately, the patient was minimally symptomatic. His peak troponin I was 48 ng/mL (normal range < 0.04 ng/mL). After multidisciplinary discussion, rFVIIa was discontinued since it can promote thrombosis. Neither therapeutic anticoagulation nor coronary angiography were pursued due to concerns for bleeding. The patient completed his inferior infarct without complications. His ureteral bleeding also had stopped despite holding rVIIa. Discussion: Acquired hemophilia A (AHA) is a rare entity found in individuals with no history of bleeding disorders in which autoantibodies are directed against clotting factor VIII. rFVIIa is a bypass agent that is approved for acute management of bleeding and perioperative course in AHA. Thrombotic complications are rare, reported in only 0.17% of cases, but its management is challenging. Anticoagulation can be considered depending on bleeding risk. We highlight the importance of an individualized approach with careful risk-benefit assessment and multidisciplinary discussion when managing PWH with acute coronary syndrome.

Characteristics and mechanism of reciprocal ST-segment depression in acute ST segment elevation myocardial infarction: Reciprocal ST-segment depression and ST segment elevation myocardial infarction.

At present, the mechanism of reciprocal ST-segment depression (RSTD) is unclear. ST-segment changes may be caused by the potential difference between the positive and negative electrodes, although this requires further investigation. The characteristics of RSTD and their relationship with ST-segment elevation in acute ST segment elevation myocardial infarction (STEMI) patients were analyzed. We replaced the negative electrode of the precordial leads of an inferior wall myocardial infarction patient and observed the changes in the ST-segment of the precordial leads. A total of 85 patients were included, of which 75 were patients with RSTD. All 45 patients with inferior myocardial infarction had limb lead RSTD, and 37 had anterior lead ST-segment depression. All ST-segment changes in STEMI can be explained by the proposed mechanism, and the value of ST segment depression in limb leads can be calculated by the value of ST segment elevation. In summary, the mechanism of RSTD in acute myocardial infarction may be that the action potential (AP) of the negative electrode of the lead weakens or disappears and the AP of the positive electrode may not be completely offset, resulting in ST-segment depression. Animal experimental studies are needed for further confirmation. When the negative electrode of the precordial lead is changed in acute inferior wall myocardial infarction patient, the ST-segment of the precordial lead changes accordingly. All the changes are consistent with our analysis.

The Incidence and Impact of Permanent Right Ventricular Infarction on Left Ventricular Infarct Size in Patients With Inferior ST-Segment Elevation Myocardial Infarction

Mounting evidence shows that right ventricle (RV) function carries independent prognostic influence in various disease states. This study aimed to investigate the incidence and impact of permanent RV infarction in patients with inferior ST-segment elevation myocardial infarction (STEMI) and culprit lesion in the right coronary artery (RCA). In this substudy of the DANAMI-3 (DANish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction) trial, cardiac magnetic resonance was performed in 291 patients at day 1 and follow-up 3 months after primary percutaneous coronary intervention of 674 patients with STEMI with the culprit lesion in the RCA. Final infarct was assessed using late gadolinium enhancement on cardiac magnetic resonance at 3 months. Patients with permanent RV infarction (20%) had lower ventricular function at follow-up; RV ejection fraction (EF) 47% ±6 versus 50% ± 5 (p <0.005) and left ventricular (LV) EF 56% ± 8 versus 60% ± 9 (p <0.006). Furthermore, patients with permanent RV infarction had a higher incidence of microvascular obstruction 39 (67%) versus 81 (39%) (p <0.001), larger final LV infarct size 16% ±8 versus 10% ± 8 (p <0.001) and larger LV area at risk 33% ± 10 versus 29% ± 9 (p <0.001). Permanent RV infarction was an independent predictor of final LV infarct size (p <0.001) but was not associated with LVEF (β=-0.0; p=0.13) in multivariable analyses. In conclusion, permanent RV infarction was seen in 20% of patients with inferior STEMI and culprit lesion in RCA and independently predicted final LV infarct size. However, permanent RV infarction did not predict overall LV function. LGE was used to detect infarct location and quantify infarct size.17 LGE in RV free wall on follow-up CMR was considered as permanent infarction. LGE images were obtained 10 minutes after intravenous injection of 0.1-mmol/kg body weight of gadolinium-based contrast (Gadovist; Bayer Schering, Berlin, Germany) using an electrocardiogram (ECG)-triggered inversion-recovery sequence. The inversion time was adjusted to null the signal from the normal myocardium. Short-axis images were acquired from the atrioventricular plane to the apex with adjacent 8-mm slices. The remaining protocol has been described previously.16.

Right ventricular involvement in inferior ST-segment elevation myocardial infarction – incidence and significance in mid and long-term follow-up

Right ventricular involvement in inferior ST-segment elevation myocardial infarction – incidence and significance in mid and long-term follow-up

Pacemaker-Mediated Tachycardia Interpolated Into Ventricular Tachycardia

In a 77-year-old patient with a history of inferior myocardial infarction and dual-chamber pacemaker (Effecta DR, Biotronik) implanted for carotid sinus syndrome, a routine Holter electrocardiogram recorded 3 consecutive tachycardias: irregular monomorphic ventricular tachycardia (VT), pacemaker-mediated tachycardia (PMT), and reoccurred VT (re-VT) of the same morphology as the initial one, but regular and faster than the PMT (Fig. 1).The pacemaker settings were as follows: DDD mode; pacing rate, 50 to 130 bpm; programmed atrioventricular delay, paced 145 ms and sensed 105 ms; and postventricular atrial refractory period (PVARP), 250 ms and 400 ms following premature ventricular contraction.What was the most likely mechanism of this arrhythmia?B) PMT was triggered by atrial premature beat and terminated by the re-VT (Fig. 2) Concerning the mode of the PMT initiation, the VT could not trigger PMT because its retrograde P wave (in Fig. 2, stars denote retrograde P waves; those of the VT and re-VT are marked below and those of the PMT above the middle electrocardiographic channel) occurred during the PVARP (gray horizontal marks in the ladder diagram). Given that the interrogation showed no pacemaker malfunctions and that the electrocardiogram showed no artifacts, an atrial ectopic beat (with isoelectric P wave) is the only likely trigger for PMT.Concerning the mode of PMT termination, the episode was too short to activate the device's PMT termination algorithm. Furthermore, the retrograde P wave from the last PMT beat, which appeared after 344 ms, indicates that retrograde conduction has been prolonged, but without occurrence of a block that would have stopped the PMT. Thus, the re-VT is what terminated the PMT by the first impulse following fusion (f2 in Fig. 2), which depolarized ventricles before the possible onset of the next paced beat. Retrograde conduction prolongation (by 24 ms) and programmed atrioventricular delay prolongation (by 50 ms, for Biotronik's PMT status confirmation) during the last PMT cycle provided a time for the onset of the re-VT and thus indirectly participated in the PMT termination.Based on the constant cycle length (382 ms) of the re-VT during the prolongation of ventriculoatrial conduction (from 170 to 240 ms), the re-VT was most probably microreentrant. Different retrograde conduction times of the VT (160 ms) and PMT (315 ms) might suggest the existence of a dual retrograde conduction with separate pathways for each of the 2 tachycardias, but any evidence for such speculation is lacking. In any case, this case illustrates the complexity of possible interactions between spontaneous and device-mediated arrhythmias.

Biochemical, coronary angiographic and echocardiographic parameters in inferior acute myocardial infarction with right ventricle injury

Background: The involvement of the right ventricular (RV) myocardium in inferior acute myocardial infarction (AMI) increases the risk of complication and death rates, which makes it important to timely identify this type of myocardial infarction.&#x0D; Aim: To assess the value of functional, biochemical, coronary angiographic and ultrasound parameters in the patients in their productive age with inferior AMI, in order to identify the RV injury before and after percutaneous coronary intervention (PCI).&#x0D; Materials and methods: This cohort prospective study included 141 patients with inferior AMI and ST elevation (26 women aged up to 60 years and 115 men aged up to 65 years), admitted to the emergency of the Medical Unit of Kazan (Volga region) Federal University from 2019 to 2021. The patients past history, clinical, biochemical and ultrasound data were obtained on admission and at discharge from the hospital. The two-dimensional speckle tracking echocardiography was performed at days 5 to 7 after PCI. The results are given as median values and 25% and 75% quartiles (Ме [Q1; Q3]).&#x0D; Results: According to electrocardiographic signs, 41.8% (n = 59) patients with inferior AMI comprised the group with the RV injury. There were no differences in the myocardial injury biomarker levels between the groups on admission (р = 0.31 and p = 0.786, respectively). The coronary angiography showed that the index artery was the right coronary artery in 100% (n = 59) cases with the RV injury and in 67.1% (n = 55, р 0.001) of the cases without the RV injury. Proximal involvement was 2.7 more common in biventricular infarction, than in the isolated inferior one (р = 0.013). During PCI, the RV involvement significantly increased the risk of complications (in 28 (47.5%) and 18 (22.0%) of the cases, respectively, р 0.001), among them being the need in a temporary pacemaker placement (8 (13.6%) and 2 (2.4%) patients, р = 0.027). Echocardiography showed worse parameters of global and local contractility of both ventricles in the group with the RV involvement in the inferior AMI. The left ventricular (LV) ejection fraction decreased from 55% [51; 57] to 52% [47; 56] (р = 0.005); global RV deformity from -15.2% [-18.5; -13.4] to -12.3% [-15.6; -10.6] (р 0.001); total number of segments with local contractility abnormalities increased from 2 [1; 3] to 5 [3; 6] (р 0.001).&#x0D; Conclusion: The study has confirmed that the involvement of RV into inferior LV AMI in the patients of productive age should be verified by abnormalities of electrocardiographic, biochemical, coronary angiographic and ultrasound parameters. To document the RV injury before PCI, ST elevation in additional right chest leads (V3RV4R) was most informative, whereas after PCI, it was the finding of abnormal local contractility of basal and medial inferior RV segments by two-dimensional echocardiography and decreased longitudinal RV deformation by speckle tracking.

FACTORS INFLUENCING THE OUTCOME OF THROMBOLYSIS IN ACUTE MYOCARDIAL INFARCTION

Coronary heart disease (CHD) is a worldwide health epidemic. It has been defined as “impairment of heart function due to inadequate blood flow to heart compared to its needs caused by obstructive changes in the coronary circulation to the heart”(1). It is the cause of 25-30% of deaths in most of the industrialized countries. In India also it is a major public health problem. It is aptly called by WHO as the 'modern epidemic'. The increasing incidence of coronary heart disease may be a reflection of increased longevity, adoption of high fat diet based on meats decreased exercise, modern lifestyle, made possible by increasing affluence.The present study is to ascertain the factors influencing outcome of thrombolysis in acute MI and concludes that Gender and Pre infarction not influence the success rate of thrombolysis, Better success rate has been seen in those consuming alcohol and smokers had a lesser success rate than non smokers but statistically not significant. Hypertensives did not show any difference with non hypertensives in the success rate. Diabetics did not differ much from non diabetics with respect to the success rate of thrombolysis. Inferior wall myocardial infarction had a better success rate than anterior wall myocardial infarctions. Those who are having short window period had a better success rate after thrombolysis. Shorter the window period higher the success rate.

ST Segment Score on Initial Electrocardiogram (ECG) as a Predictor of In-Hospital Outcome of ST-Elevated Myocardial Infarction (STEMI) Patients

Introduction: The process of myocardial infarction progresses over several hours and therefore most patients present when it is still possible to salvage myocardium. ECG is usually a sensitive and specific way of confirming diagnosis. ST segment score (STSS) in myocardial infarction is emphasized but not often quantified. HJ Wellens gave cutoff for STSS in anterior wall MI (AWMI)of 12 mm and inferior wall MI (IWMI)of 7 mm. In this study the predictive value of ST Segment Score (STSS) with patients of STEMI on admission ECG &amp; after thrombolysis had been assessed. Objectives: Identify patients at higher risk early in the course of their hospital admission &amp; correlation of initial ECG and post thrombolysis ECG regarding clinical outcome. Materials and Methods:Considering inclusion and exclusion criteria 112 patients admitted in CCU, DMCH during october 2007 to september 2008 were studied of which 64 were inferior STEMI and 48 were anterior STEMI. Like admission ECG, after 90 minutes of starting thrombolytic,another ECG was recorded and calculated. Echocardiography was done for each patient before discharge. Data was collected in a pre-designed form. Results: The mean age of Group-I was 55.2±12.2 years and that of Group-II 56.9±14.1 years, Group-III 59.2±11.7 years,Group-IV 55.0±12.6 years. Of the 30 patients studied in Group-I 76.7% was male and 23.3% female. Smoking was the most prevalent (60% in Group I, 58.8% in Group II) risk factor. In post thrombolytic ECG shows that in Group-I mean sum of ST elevation decreased to 3.9 ± 1.1 mm from 4.8 ± 1.2 mm. which was approximately (45+14)% of ST resolution, in Group-II(50+19%),in Group-III (55+19)%, in Group-IV(45+23)%. Conclusion: Significant differences were seen in chest pain, killip class,arrhythmia, echocardiographic LVEF, duration of hospital stay in patients with AWMI &amp; STSS above 12 mm and IWMI &amp; STSS above 7 mm in comparison with below these level even after use of thrombolytics. Medicine Today 2022 Vol.34(2): 88-92