What acute cardiac care physicians need to know from the latest 2022 ESC Guidelines for ventricular tachycardia and sudden cardiac death

The present paper summarizes and comments on the latest 2022 ESC guidelines on ventricular tachycardia and sudden cardiac death. Most relevant recommendations for acute cardiovascular care physicians are addressed, particularly, in the fields of coronary artery disease, dilated cardiomyopathy, and inflammatory diseases. New recommendations encompass the implantation of a defibrillator (ICD) in the setting of acute myocarditis. Furthermore, the pathophysiology of the electrical storm including involved molecular pathways as well as the angry Purkinje fibre syndrome is presented and discussed.

Atrial high-rate episode burden and stroke risks for patients with device-detected subclinical atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Atrial high-rate episode (AHRE) and stroke are related; however, the magnitude of the correlations between different AHRE burdens and stroke remains unknown. We analysed studies that evaluated this relationship.

METHODS

We searched for observational controlled studies that reported the associations of different AHRE burdens with stroke in populations with cardiac implantable electronic devices (CIEDs). The primary endpoint was stroke or thrombosis during follow-up. We performed subgroup analyses according to the classification criteria and research design of the included studies.

RESULTS

Of the 5985 studies identified, 9 met the eligibility criteria and included 42,958 patients. Patients with low and high AHRE burdens had a 1.2-fold risk of stroke (no heterogeneity) and a 2.52-fold risk of stroke (moderate heterogeneity), respectively. After excluding studies analysing the atrial fibrillation history, no significant difference in progressive stroke risk was observed for patients with a low AHRE burden (without significant heterogeneity). An increased likelihood of stroke was observed for patients with a high AHRE burden (decreased heterogeneity). Four of the nine studies classified high and low AHRE burdens using the longest AHRE time. Five studies classified high and low AHRE burdens based on the median of the total AHRE time as the cutoff value. Low and high AHRE burdens were more closely related to stroke when classified by the total AHRE duration than when classified by the single longest AHRE duration.

CONCLUSIONS

For populations with CIEDs without an atrial fibrillation history, a high AHRE burden was significantly associated with stroke.

A Clinical Score for Predicting the Paroxysmal Supraventricular Tachycardia's Recurrence Risk; a Retrospective Cross-sectional Study

Introduction

Identifying prognostic variables associated with the probability of recurrent paroxysmal supraventricular tachycardia (PSVT) would aid decision-making regarding disposition of the patients. This study aims to develop a clinical scoring system to predict PSVT recurrence after adenosine administration in the emergency department (ED).

Methods

This retrospective cross-sectional study was conducted on patients who were referred to the emergency department of Ramathibodi Hospital, a university-affiliated super-tertiary care hospital in Bangkok, Thailand, with diagnosis of PSVT during a 10-year period from 01 January 2010 until 31 December 2020. The cases were divided into recurrent and non-recurrent PSVT based on the response to standard treatment and the independent predictors of recurrence were studied using multivariable logistic regression analysis.

Results

264 patients were diagnosed with PSVT and successfully converted by adenosine. 24 (9.1%) had recurrent PSVT, and 240 (90.9%) had no recurrent PSVT in the same ED visit. The risk of PSVT recurrence in ED corresponded with the history of hypertension (p = 0.059), valvular heart disease (p = 0.052), heart rate ≥ 100 (p = 0.012), and systolic blood pressure < 100 after electrocardiogram (ECG) converted to sinus rhythm (p = 0.022) and total dose of adenosine (p = 0.002). We developed a clinical prediction score of PSVT recurrence with an accuracy of 79.5%. A score of 0 (low risk), 1-2 (moderate risk), and > 2 (high risk) had a positive likelihood ratio (LR+) of 0.31, 0.56 and 2.33, respectively.

Conclusion

It seems that, using the PSVT recurrence score we could screen the high-risk patients for PSVT recurrence (score>2) who need to be observed for at least 6-12 hours and receive cardiologist consultation in ED. In addition, the moderate and low-risk group (score 0-2) need to be observed for 1 hour and can be discharged from ED.

Tachycardia Changes Increase Neurological Deterioration in Patients with Acute Non-Cardioembolic Stroke: An ADS Post-Hoc Analysis

AIM

A previous randomized study showed that dual antiplatelet therapy (DAPT) with aspirin and cilostazol is not superior to aspirin monotherapy for patients with acute non-cardioembolic stroke; however, the reason for this remains uncertain. We focused on the unusual side effects of cilostazol, namely, tachycardia changes, and validated their influence on patients with acute non-cardioembolic stroke.

METHODS

This post-hoc study extracted data from the acute aspirin plus cilostazol dual therapy study (ADS) registry, a multicenter, prospective, randomized, open-label trial. Patients were randomly allocated to the dual group (aspirin plus cilostazol) and the aspirin monotherapy group (aspirin alone). Tachycardia changes were defined as ≥ 5% heart rate increase at 48 h after admission compared with that at admission. Baseline data and outcomes were validated with four divided groups: aspirin-non-tachycardia changes (AN), aspirin-tachycardia changes (AT), dual-non-tachycardia changes (DN), and dual-tachycardia changes (DT).

RESULTS

Finally, 1,188 patients were analyzed in this ADS post-hoc analysis (aspirin monotherapy group, 594; dual group, 594). The proportion of change in tachycardia was 19.2% in the aspirin monotherapy group and 38.2% in the dual group (p＜0.001^＊＊＊). Although the recurrences of symptomatic stroke and transient ischemic attack were not significantly different, the neurological deterioration was significantly different among the AN, AT, DN, and DT groups (p＜0.05^＊).

CONCLUSIONS

Tachycardia changes increase neurological deterioration even in patients with non-cardioembolic acute stroke. DAPT consisting of aspirin and cilostazol increases the proportion of tachycardia changes and is not superior to aspirin monotherapy.

Decreased Heart Rate Variability in COVID-19

Purpose

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which primarily infects the lower airways and binds to angiotensin-converting enzyme 2 (ACE2) on alveolar epithelial cells. ACE2 is widely expressed not only in the lungs but also in the cardiovascular system. Therefore, SARS-CoV-2 can also damage the myocardium. This report aimed to highlight decreased heart rate variability (HRV) and cardiac injury caused by SARS-CoV-2.

Materials and Methods

We evaluated three COVID-19 patients who died. Patients' data were collected from electronic medical records. We collected patient's information, including baseline information, lab results, body temperature, heart rate (HR), clinical outcome and other related data. We calculated the HRV and the difference between the expected and actual heart rate changes as the body temperature increased.

Results

As of March 14, 2020, 3 (2.2%) of 136 patients with COVID-19 in Tianjin died in the early stage of the COVID-19 epidemic. The immediate cause of death for Case 1, Case 2, and Case 3 was cardiogenic shock, cardiac arrest and cardiac arrest, respectively. The HRV were substantially decreased in the whole course of all three cases. The actual increases in heart rate were 5 beats/min, 13 beats/min, and 4 beats/min, respectively, less than expected as their temperature increased. Troponin I and Creatine Kinase MB isoenzyme (CK-MB) were substantially increased only in Case 3, for whom the diagnosis of virus-related cardiac injury could not be made until day 7. In all three cases, decreased in HRV and HR changes occurred earlier than increases in cardiac biomarkers (e.g., troponin I and CK-MB).

Conclusions

In conclusion, COVID-19 could affect HRV and counteract tachycardia in response to increases in body temperature. The decreases of HRV and HR changes happened earlier than the increases of myocardial markers (troponin I and CK-MB). It suggested the decreases of HRV and HR changes might help predict cardiac injury earlier than myocardial markers in COVID-19, thus its early identification might help improve patient prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44231-022-00024-1.

Postural orthostatic tachycardia syndrome and orthostatic hypotension in post-acute sequelae of COVID-19 during pregnancy: a case report

BACKGROUND

Patients with post-acute sequelae of COVID-19 (PASC) often experience the addition of new symptoms after recovery from COVID-19 illness. These may include orthostatic intolerance and autonomic dysfunction, and postural orthostatic tachycardia syndrome has been described to occur in a proportion of patients with PASC.

CASE SUMMARY

In this report, we present a 32-year-old pregnant woman (G3P2) who experiences severe orthostatic symptoms as part of her PASC syndrome, which is decoupled from normal physiologic changes of pregnancy. At 25 weeks of gestation, she was evaluated for increasing episodes of dyspnoea, marked tachycardia with minimal exertion, intermittent non-exertional chest pain, and presyncope. This patient had a moderate course of COVID-19 at 12 weeks of gestation, for which she received monoclonal antibody therapy (casirivimab/imdevimab). The patient then had complete resolution of COVID-19 symptoms and felt well for 1 month prior to developing orthostatic symptoms at 25 weeks of gestation. Evaluation with a NASA Lean Test revealed marked orthostatic tachycardia, as well as delayed orthostatic hypotension. Given her COVID-19 illness 4 months prior, PASC involving autonomic dysfunction was diagnosed.

DISCUSSION

Patients with orthostatic symptoms in PASC should be carefully evaluated with dedicated active stand tests, such as the NASA Lean Test, to characterize the autonomic response to standing. In pregnant patients, an understanding of normal pregnancy physiology is crucial to correctly identify abnormal findings in such tests.

Postural orthostatic tachycardia syndrome as a sequela of COVID-19

Postural orthostatic tachycardia syndrome (POTS) is a complex multisystem disorder characterized by orthostatic intolerance and tachycardia and may be triggered by viral infection. Recent reports indicate that 2%-14% of coronavirus disease 2019 (COVID-19) survivors develop POTS and 9%-61% experience POTS-like symptoms, such as tachycardia, orthostatic intolerance, fatigue, and cognitive impairment within 6-8 months of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Pathophysiological mechanisms of post-COVID-19 POTS are not well understood. Current hypotheses include autoimmunity related to SARS-CoV-2 infection, autonomic dysfunction, direct toxic injury by SARS-CoV-2 to the autonomic nervous system, and invasion of the central nervous system by SARS-CoV-2. Practitioners should actively assess POTS in patients with post-acute COVID-19 syndrome symptoms. Given that the symptoms of post-COVID-19 POTS are predominantly chronic orthostatic tachycardia, lifestyle modifications in combination with the use of heart rate-lowering medications along with other pharmacotherapies should be considered. For example, ivabradine or β-blockers in combination with compression stockings and increasing salt and fluid intake has shown potential. Treatment teams should be multidisciplinary, including physicians of various specialties, nurses, psychologists, and physiotherapists. Additionally, more resources to adequately care for this patient population are urgently needed given the increased demand for autonomic specialists and clinics since the start of the COVID-19 pandemic. Considering our limited understanding of post-COVID-19 POTS, further research on topics such as its natural history, pathophysiological mechanisms, and ideal treatment is warranted. This review evaluates the current literature available on the associations between COVID-19 and POTS, possible mechanisms, patient assessment, treatments, and future directions to improving our understanding of post-COVID-19 POTS.

Uncontrolled high blood pressure under total intravenous anesthesia with propofol and remifentanil: A case report

BACKGROUND

Although propofol generally reduces blood pressure, rarely, it causes hypertension. However, the mechanism by which propofol increases blood pressure has not been established, and so far, there are only a few reported cases.

CASE SUMMARY

A 46-year-old woman, diagnosed with thyroid cancer, was administered general anesthesia with propofol and remifentanil for a thyroid lobectomy. An increase in the concentrations of intravenous anesthetics further increased her blood pressure. The blood pressure remained stable when anesthesia was maintained with sevoflurane and remifentanil after the interruption of propofol administration.

CONCLUSION

We concluded that propofol administration was the cause of increased blood pressure.

Wearable Technology Leads to Initial Workup of Graves' Disease in an Adolescent Female

Graves' disease is the most common form of hyperthyroidism in the pediatric population. While the most prevalent symptoms seen in children with Graves' disease include goiter and excessive sweating (Minamitani et al., 2017), diagnosis is frequently delayed due to presentation with non-specific symptoms (Léger et al., 2018). This case report is of a 12-year-old female who presented to her pediatrician with a one month history of episodes of tachycardia both with physical exertion and at rest. Notably, these episodes were discovered on her electronic smartwatch by its heart rate monitoring feature. Further pertinent positives elicited in the patient's review of systems included increasing anxiety, diaphoresis, intermittent hand tremors, and recent weight loss. These findings led to further workup that included thyroid studies, culminating in a diagnosis of Graves' disease. Indeed, this patient's smartwatch aided in her initial presentation to her physician and allowed for prompt workup and diagnosis. There exist limited studies to date on the use of smartwatches to detect cardiac-related conditions in children, which may be due to the absence of Food and Drug Administration approval for certain cardiac-related smartwatch features in this patient population.

A Comprehensive Review of Left Ventricular Summit Ventricular Arrhythmias

The catheter ablation of idiopathic ventricular arrhythmias is accepted as a first-line treatment as it successfully eliminates about 90.0% of such arrhythmias. One of the most challenging ventricular arrhythmias originates from the left ventricular summit (LVS), a triangular epicardial space with the left main bifurcation as its apex. This area accounts for about 14.0% of LV arrhythmias. The complex anatomy of this region, accompanied by proximity to the major epicardial coronary arteries and the presence of a thick fat pad in this region, renders it a challenging area for catheter ablation. This article presents a review of the anatomy of the LVS and relevant regions and discusses novel mapping and ablation techniques for eliminating LVS ventricular arrhythmias. Additionally, we elaborate on the electrocardiographic (ECG) manifestations of arrhythmias from the LVS and their successful ablation via the direct approach and the adjacent structures.

Understanding the EKG changes in methemoglobinemia

Methemoglobin is a form of hemoglobin that has been oxidized, changing its heme iron configuration from the ferrous to the ferric state. Unlike normal hemoglobin, methemoglobin does not bind oxygen and as a result, cannot deliver oxygen to the tissues. At the presentation in the emergency department, an electrocardiogram (EKG) is usually performed as a reflex for patients admitted for shortness of breath to rule out acute coronary syndrome. Very limited data is available on EKG abnormalities in patients with methemoglobinemia. In this study, we retrospectively analyzed the pattern of EKG changes in patients with methemoglobinemia.

Postural tachycardia syndrome among adolescents

Postural tachycardia syndrome (PoTS) is a polymorphic clinical syndrome that is underdiagnosed, especially in adolescents. It is a form of dysautonomia, but its exact physiopathology remains elusive. Several pathologies can mimic PoTS; it is characterized by heterogeneous symptoms that accompany a disproportionate tachycardia upon the upright position. It can significantly impact the patients' quality of life. Only a Schellong test is useful for making the diagnosis. Treatment in PoTS is primarily symptomatic with the main goal being to restore the patient's condition as quickly as possible. We report here the diagnosis and management of seven adolescents, aged 11-16, who have been followed up since 2015.

[Case report: persistent fever after SARS-CoV-2 infection]

A 44-year-old man had persistent fever following a severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection. Because of progressive sinus tachycardia, thyroid hormones were measured which showed hyperthyroidism. Thyroid sonography revealed enlargement of the thyroid gland with hypoechoic areas with blurred margins. We diagnosed subacute granulomatous thyroiditis associated with SARS-CoV‑2 infection and initiated therapy with prednisolone. This therapy resulted in rapid improvement of the patient's clinical condition and complete remission after three months.

[Heart rate control in shock]

Heart rate is well established in the diagnosis of shock; however, the mechanisms regulating heart rate, systemic resistance and blood pressure remain unclear. The concept of heart rate control in shock-related tachycardia has been known for about 50 years. Elevated heart rates in septic shock have been identified as an indicator of increasingly inefficient hemodynamics, worsening perfusion and organ function as well as of an unfavourable prognosis. Many drugs used for heart rate control also lower blood pressure. The challenge of this therapeutic concept is achieving optimal heart rate control without provoking critical hypotension. Only in recent years has the development of highly cardioselective, short- and ultrashort-acting β‑blockers such as esmolol and landiolol made it possible to prove the feasibility and usefulness of heart rate control in certain types of shock.

The Relationship Between Tachycardia After Laparoscopic Sleeve Gastrectomy and the Development of Postoperative Complications

BACKGROUND

Bariatric surgery can be associated with severe complications. Tachycardia is an important indicator of certain complications, such as anastomotic leak and hemorrhage. Our aim was to examine the relationship between tachycardia following sleeve gastrectomy and the appearance of associated complications.

METHODS

Patients who underwent sleeve gastrectomy over a 2-year period were included in the study. Participants were divided into two groups: the first included patients who suffered from postoperative tachycardia and the second patients with normal postoperative heart rates. Complications in both groups were examined. Other parameters that predict the onset of complications were also reviewed.

RESULTS

A total of 457 patients were included. Postoperative tachycardia was measured in 181 (39.6%) patients; 17 (3.7%) suffered from bleeding and 4 (1%) from staple line leakage. Postoperative bleeding was more common among patients with tachycardia than among those without (14 (7.7%) vs. 3 (1.1%), respectively). Patients in the tachycardia group had more staple line leakages than those in the normal heart rate group (3 (2%) vs. 1 (0%), respectively); tachycardia was also attributed to postoperative pain or other minor complications in 160 (88%) patients. Age ≥ 40 years was found to be predictive factor for postoperative complications.

CONCLUSIONS

The most common causes of tachycardia postoperatively were pain and minor complications. Tachycardia is an essential indicator of postoperative minor and major complications, mainly staple line leakage and bleeding. This should prompt immediate medical intervention in order to avoid serious adverse events.

NaHCO3, L-arginine, and vitamin C supplemented vegetable diet ameliorates tachycardia and polycythemia in the broiler chicken

The study aimed to investigate if vegetable-based high-energy mash diets supplemented with NaHCO₃, L-arginine + vitamin C, and vegetable oils were effective against tachycardia and polycythemia in the broiler chicken. A total of 256 Ross-308 day-old male broiler chicks were randomly distributed into eight dietary treatment groups in a three-way ANOVA with 2 × 2 × 2 factorial arrangement (three factors, i.e., NaHCO₃, L-arginine + vitamin C, and vegetable oil each with two levels, e.g., 0 and 0.1% of NaHCO₃ and L-arginine + vitamin C; 3 and 4% of vegetable oil supplemented with basal diet) for a period of 35 days. Iso-caloric and iso-nitrogenous diets were formulated and supplied ad libitum. The final live weight (FLW), average daily feed intake (ADFI), average daily gain (ADG), feed efficiency (FE), carcass traits, cardio-pulmonary morphometry, total protein (TP), hemoglobin (Hb), triiodothyronine (T₃), incidence of tachycardia, and polycythemia were examined. Supplementation of NaHCO₃ increased 2.2% ADFI, 5.5% FE, and 23.2% TP. The L-arginine + vitamin C increased 2.4% FLW and decreased 1.9% heart rate. Vegetable oil increased 1.3% ADFI, 4.2% ADG, 8.6% FE, 23.1% Hb, and 15.5% PCV. The NaHCO₃, L-arginine + vitamin C, and vegetable oil additively interacted to increase 31.5% T₃ at the expense of 21.1% of the weight of the right ventricle (RV). The RV:TV, carcass traits, and hemato-biochemical indices remained within normal range irrespective of the levels of the supplementations of the test ingredients. It was concluded that vegetable-based high-energy mash diets were not susceptible to tachycardia and polycythemia. The addition of NaHCO₃ and L-arginine + vitamin C ameliorated the propensity of tachycardia and polycythemia without deteriorating performance, carcass traits, and hemato-biochemical indices of the broiler chicken in a dose-dependent manner.

Changes in intrathoracic pressure, not arterial pulsations, exert the greatest effect on tracer influx in the spinal cord

BACKGROUND

Cerebrospinal fluid (CSF) circulation in the brain has garnered considerable attention in recent times. In contrast, there have been fewer studies focused on the spine, despite the expected importance of CSF circulation in disorders specific to the spine, including syringomyelia. The driving forces that regulate spinal CSF flow are not well defined and are likely to be different to the brain given the anatomical differences and proximity to the heart and lungs. The aims of this study were to determine the effects of heart rate, blood pressure and respiration on the distribution of CSF tracers in the spinal subarachnoid space, as well as into the spinal cord interstitium.

METHODS

In Sprague Dawley rats, physiological parameters were manipulated such that the effects of spontaneous breathing (generating alternating positive and negative intrathoracic pressures), mechanical ventilation (positive intrathoracic pressure only), tachy/bradycardia, as well as hyper/hypotension were separately studied. To investigate spinal CSF hydrodynamics, in vivo near-infrared imaging of intracisternally infused indocyanine green was performed. CSF tracer transport was further characterised with in vivo two-photon intravital imaging. Tracer influx at a microscopic level was quantitatively characterised by ex vivo epifluorescence imaging of fluorescent ovalbumin.

RESULTS

Compared to mechanically ventilated controls, spontaneous breathing animals had significantly greater movement of tracer in the subarachnoid space. There was also greater influx into the spinal cord interstitium. Hypertension and tachycardia had no significant effect on spinal subarachnoid spinal CSF tracer flux and exerted less effect than respiration on tracer influx into the spinal cord.

CONCLUSIONS

Intrathoracic pressure changes that occur over the respiratory cycle, particularly decreased intrathoracic pressures generated during inspiration, have a profound effect on tracer movement after injection into spinal CSF and increase cord parenchymal tracer influx. Arterial pulsations likely drive fluid transport from perivascular spaces into the surrounding interstitium, but their overall impact is less than that of the respiratory cycle on net tracer influx.

Comparing methods of adenosine administration in paroxysmal supraventricular tachycardia: a pilot randomized controlled trial

Background

Intravenous adenosine is the recommended treatment for paroxysmal supraventricular tachycardia (PSVT). There is no official recommended method of giving adenosine. We compared the success rates between a standard and alternative method of first dose intravenous adenosine in PSVT.

Methods

A pilot parallel randomized controlled study was conducted in the emergency department of a tertiary care hospital. Eligible patients were stable PSVT adult patients. We used block randomization and divided them into two groups, the standard method (double syringe technique of 6 mg of adenosine), and the alternative method (similar to the standard method, then immediately followed by elevating the arm to 90° perpendicular to a horizontal plane for 10 s). The primary outcome was the success rate of electrocardiogram (ECG) response which demonstrated termination of PSVT (at least two-fold of the RR-interval widening or sinus rhythm conversion). Secondary outcomes were complications within one minute after the injection.

Results

We allocated 15 patients in each group and analyzed them as intention-to-treat. The success rate was 86.7% in the alternative group and 80% in the standard group (risk difference 6.7%, 95% confidence interval − 19.9 to 33.2%, P 1.00). Complications within one minute after adenosine injection were also similar in both groups, 14 of 15 patients (93%) in each group had no complications, without significant difference.

Conclusions

No evidence of the difference between alternative and standard methods occurred, in terms of the success rate of ECG response and complications within one minute after adenosine injection. The standard method of adenosine injection is a safe, easy-to-administer, and widely available treatment for PSVT.

Trial Registration: TCTR20200609001.

Using a smartwatch to record an electrocardiogram in the pediatric population

The accuracy of smartwatch ECG recordings in adults has been demonstrated primarily in the automated diagnosis of atrial fibrillation. While the detection of atrial fibrillation is a priority among adults given the arrhythmia's prevalence and actionable ramifications, the potential value of smartwatch ECG recordings in children differs considerably. In this case series, we will describe some examples of smartwatch ECGs recorded in children, highlighting the feasibility and potential indications of this technology in the pediatric population.

Estimation of cardiac QTc intervals in people prescribed antipsychotics: a comparison of correction factors

BACKGROUND

A prolonged electrocardiogram (ECG) QT interval is associated with cardiac events and increased mortality. Antipsychotics can prolong the QT interval. The QT interval requires correction (QTc) for heart rate using a formula or QT-nomogram. The QT and QTc can be calculated automatically by the ECG machine or manually; however, machine-measured QT(c) intervals may be inaccurate.

OBJECTIVE

We aimed to investigate the mean QTc and proportion of prolonged QTc intervals in people taking antipsychotic medicines.

METHODS

We conducted an observational retrospective chart review and data analysis of all consecutive patients taking antipsychotics, with an ECG record, admitted to the psychiatric unit of a large tertiary hospital in Brisbane, Australia, between 1 January 2017 and 30 January 2019. We investigated the mean QTc of people taking antipsychotics to determine differences using (a) machine versus manual QT interval measurement and (b) QTc correction formulae (Bazett, Fridericia, Framingham, Hodges and Rautaharju) and the QT-nomogram. We also determined the number of people with a prolonged QTc using different methods and compared rates of prolonged QTc with antipsychotic monotherapy and polypharmacy.

RESULTS

Of 920 included people, the mean (±SD) machine-measured, Bazett-corrected QT interval (recorded from the ECG) was 435 ms (±27), significantly longer (p < 0.001) than the mean manually measured corrected QT intervals with Fridericia 394 ms (±24), Framingham 395 ms (±22), Hodges 398 ms (±22) and Rautaharju 400 ms (±24) formulae. There were significantly more people with a prolonged QTc using machine-measured QT and the Bazett formula (12.0%, 110/920) when compared with manually measured QT and the Fridericia formula (2.2%, 20/920) or QT-nomogram (0.7%, 6/920). Rates of QTc prolongation did not differ between people taking antipsychotic polypharmacy compared with monotherapy.

CONCLUSION

Machine-measured QTc using the Bazett formula overestimates the QTc interval length and number of people with a prolonged QTc, compared with other formulae and the QT-nomogram. We recommend manually measuring the QT and correcting with the Fridericia formula or QT-nomogram prior to modifying antipsychotic therapies.

Effect of landiolol in patients with tachyarrhythmias and acute decompensated heart failure (ADHF): a case series

Tachycardia and rapid tachyarrhythmias are common in acute clinical settings and may hasten the deterioration of haemodynamics in patients with acute decompensated heart failure (ADHF), treated with inotropes. The concomitant use of a short‐acting β1‐selective beta‐blocker, such as landiolol, could rapidly and safely restore an adequate heart rate without any negative inotropic effect. We present a case series of five patients with left ventricular dysfunction, admitted to our Intensive Cardiac Care Unit with ADHF deteriorated to cardiogenic shock, treated with a combination of landiolol and inotropes. Landiolol was effective in terms of rate control and haemodynamics optimization, enabling de‐escalation of catecholamine dosing in all patients. The infusion was always well tolerated without hypotension. In conclusion, a continuous infusion of a low dose of landiolol (3–16 mcg/kg/min) to manage tachycardia and ventricular or supraventricular tachyarrhythmias in haemodynamically unstable patients may be considered.

Alice in Wonderland Syndrome-Like Seizure and Refractory Supraventricular Tachycardia

Alice in Wonderland syndrome (AIWS) is a rarely curious visual perceptual disorder which has been associated with diverse neurologic and psychiatric problems. It may be a manifestation in migraine, epileptic seizures, encephalitis, other brain lesions, medication-related side effects, schizophrenia, and depressive disorders. Principal character of AIWS is the disproportion between the external world and the self-image in which micropsia (objects appear smaller), macropsia (objects appear larger), and teleopsia (objects appear further away) are frequently reported. The cases of temporal lobe epilepsy may present with complex visual auras of visual distortions (e.g., micropsia and macropsia) like AIWS. We report an unusual case of an elderly man who presented with AIWS, focal impaired awareness seizures, ictal tachyarrhythmia, multiple episodes of transient visual disturbances of macropsia and transient loss of consciousness. During those symptoms, telemetry showed self-limited supraventricular tachycardia several times which could not be regulated with heart rate-controlled medication. The electroencephalography was later tested and showed rhythmic theta activity over the right cerebral hemisphere. He was treated with levetiracetam, and all his symptoms and tachyarrhythmias were gradually resolved thereafter. Refractory response to treatment would remind the physicians to reassess for the correct diagnosis.

Paramedic Rhythm Interpretation Misclassification is Associated with Poor Survival from Out-of-Hospital Cardiac Arrest

BACKGROUND

Early recognition and rapid defibrillation of shockable rhythms is strongly associated with survival in out of hospital cardiac arrest (OHCA). Little is known about the accuracy of paramedic rhythm interpretation and its impact on survival. We hypothesized that inaccurate paramedic interpretation of initial rhythm would be associated with worse survival.

METHODS

This is a retrospective cohort analysis of prospectively collected OHCA data over a nine-year period within a single, urban, fire-based EMS system that utilizes manual defibrillators equipped with rhythm-filtering technology. We compared paramedic-documented initial rhythm with a reference standard of post-event physician interpretation to estimate sensitivity and specificity of paramedic identification of and shock delivery to shockable rhythms. We assessed the association between misclassification of initial rhythm and neurologically intact survival to hospital discharge using multivariable logistic regression.

RESULTS

A total of 863 OHCA cases were available for analysis with 1,756 shocks delivered during 542 (63%) resuscitation attempts. Eleven percent of shocks were delivered to pulseless electrical activity (PEA). Sensitivity and specificity for paramedic initial rhythm interpretation were 176/197 (0.89, 95% CI 0.84-0.93) and 463/504 (0.92, 95% CI 0.89-0.94) respectively. No patient survived to hospital discharge when paramedics misclassified the initial rhythm.

CONCLUSIONS

Paramedics achieved high sensitivity for shock delivery to shockable rhythms, but with an 11% shock delivery rate to PEA. Misclassification of initial rhythm was associated with poor survival. Technologies that assist in rhythm identification during CPR, rapid shock delivery, and minimal hands-off time may improve outcomes.

Diagnosis and management of arrhythmias in pregnancy

Arrhythmias are the most common cardiac complications occurring in pregnancy. Although the majority of palpitations in pregnancy may be explained by atrial or ventricular premature complexes, the full spectrum of arrhythmias can occur. In this article, we establish a systematic approach to the evaluation and management of arrhythmias in pregnancy. Haemodynamically unstable arrhythmias warrant urgent cardioversion. For mild cases of benign arrhythmia, treatment is usually not needed. Symptomatic but haemodynamically stable arrhythmic patients should first undergo a thorough evaluation to establish the type of arrhythmia and the presence or absence of structural heart disease. This will ultimately determine the necessity for treatment given the potential risks of anti-arrhythmic pharmacotherapy in pregnancy. We will discuss the main catalogue of anti-arrhythmic medications, which have some established evidence of safety in pregnancy. Based on our appraisal, we provide a treatment algorithm for the tachyarrhythmic pregnant patient.

Post-COVID-19 Tachycardia Syndrome: A Distinct Phenotype of Post-Acute COVID-19 Syndrome

In this paper we highlight the presence of tachycardia in post-acute COVID-19 syndrome by introducing a new label for this phenomenon-post-COVID-19 tachycardia syndrome-and argue that this constitutes a phenotype or sub-syndrome in post-acute COVID-19 syndrome. We also discuss epidemiology, putative mechanisms, treatment options, and future research directions in this novel clinical syndrome.