Syncopal Episodes Research Articles

FRI665 Hirata's Syndrome: Autoimmune Hypoglycemia Diagnostic Pathway, A Mexican Case Report

Abstract Disclosure: G. Gonzalez De La Cruz: None. D. Porras Farret: None. Introduction: Autoimmune hypoglycemia or Hirata syndrome is a very rare cause of hypoglycemia in western populations, as an example, in Mexico until 2015, there was only a single case reported with these characteristics. Diagnosis is based on episodes of spontaneous, fasting or postprandial hypoglycemia, with endogenous hyperinsulinism, without pancreatic lesions on imaging and positive tests. Objective: To describe the approach to a patient with hypoglycemia, specifically to those with characteristics of autoimmune hypoglycemia syndrome, as well as the general approach to hypoglycemia of endogenous origin and the differential approach in those with a history of type 2 diabetes or drug use with secondary effects. Case description: An 86-year-old woman with a history of high blood pressure, prediabetes, and osteoporosis, presented episodes of dizziness, palpitations, diaphoresis, and syncope, documenting plasma glucose of 40 mg/dl. She was attended by paramedics responding adequately to oral glucose. She was evaluated by Cardiology, Holter was performed with predominant sinus rhythm, frequent atrial extrasystoles (2%) and infrequent ventricular extrasystoles. Next, she was referred to Endocrinology for evaluation and treatment, she was taken empagliflozin as prediabetes medication, and it was suspender. Laboratory studies are requested to address hypoglycemia, with serum insulin levels greater than 600 mU/l, c-peptide 3.9 ng/ml, TSH 6.1, T4T 7.5, T3T 67.8, T4L 1.1, ALT 26 U/L, AST 18 U/L, DHL 247 U/L, GGT 26 U/L, Cortisol 13.8 mcg/dl. An MRI of the upper abdomen was performed where there is no evidence of pancreatic injury. A profile of serum hypoglycemic agents (sulfonylureas in blood) was requested, which were not detected. Subsequently, anti-insulin studies were requested, which were reported in amounts greater than 100 U/ml. The diagnosis of autoimmune hypoglycemia syndrome was made, starting management with prednisone 70 mg every 24 hours, in addition to dietary changes. Conclusion: The approach to hypoglycemia in patients without clear evidence of exogenous administration of hypoglycemic agents must be ordered, taking into account differential diagnoses such as autoimmune causes. In the case of autoimmune hypoglycemia, remission is expected at 6 months, with constant monitoring and adjustment of drugs for underlying pathologies. Presentation: Friday, June 16, 2023

THU653 Subacute Thyroiditis Following Covid19 Infection

Abstract Disclosure: E. Fanous: None. J.G. Karam: None. Background: Subacute thyroiditis is a self-limiting inflammatory condition of the thyroid gland which usually occurs as a post-viral reaction, leading to the destruction of thyroid follicular cells due to infiltration of lymphocytes. During the first outbreak of COVID-19 virus, subacute thyroiditis had been reported as a complication that may occur in patients without any previous thyroid disorder [1]. Clinical Case: A 62-year-old female patient presented with few weeks history of generalized weakness, fatigue, chills, malaise, low appetite, and unintentional weight loss of around 10lbs. She stated that she feels "internal tremors" and palpitations with heart rate increasing from baseline 60 bpm to 90bpm. She had one episode of near syncope at work prompting her presentation. She reports no change in bowel movements, no heat intolerance, no fever or night sweat, no shortness of breath, no visual changes or eyes problems. Five weeks prior to presentation, the patient was diagnosed with COVID-19 infection by PCR, with a mild disease pattern that consisted of upper respiratory symptoms lasting for few days, however she continued to feel fatigue and low appetite since then, attributing her symptoms to long-term sequelae of Coivd-19. Her past medical history is remarkable for obesity, hypercholesterolemia, and two prior Covid 19 infections: in 2020, treated with monoclonal antibodies, and early 2022. The physical exam was significant for slightly tender thyroid and heart rate of 94 bpm. Thyroid function tests were consistent with hyperthyroidism; TSH<0.01mIU/ml, FT4=2.55ng/dl (0.58-1.64), T4=19.6 mcg/dl (4.4-9.5), T3=1.45ng/ml (0.72-1.35), with negative TSI, TPO AB, and TG AB. ESR was 44mm/hr, RAI uptake and scan showed very low uptake which is indicative for subacute thyroiditis. The patient was given supportive therapy. She developed mild and transient hypothyroidism at 6 weeks follow-up with TSH of 8.59 IU/ml and FT4=0.62 ng/dl (0.89-1.76) before her thyroid tests return to normal at 9 weeks with complete resolution of her symptoms. Conclusion: Prolonged diverse symptoms following Covid19 infection are often attributed to long term Covid symptoms. Health Care providers should be aware of the possibility of subacute thyroiditis following Covid 19 infection and should obtain thyroid function tests in patients who present with malaise, decreased appetite, weight loss and palpitations in the weeks following Covid 19 infection. Reference:1. Mattar SAM, Koh SJQ, Rama Chandran S, Cherng BPZ. Subacute thyroiditis associated with COVID-19. BMJ Case Rep. doi: 10.1136/bcr-2020-237336 Presentation: Thursday, June 15, 2023

FRI262 Can Selective Serotonin Reuptake Inhibitors Unmask Underlying Polyglandular Autoimmune Syndrome Type II?

Abstract Disclosure: S. Dehghani: None. S. Kalik: None. J. Zaidan: None. A. Nisar: None. Background: Patients with chronic use of SSRIs are at increased risk of developing hyponatremia secondary to SIADH but a full work up to exclude other etiologies might still be warranted if patient has risk factors. Clinical Case: 63-year-old female with past medical history of rheumatoid arthritis and hypothyroidism secondary to Hashimoto thyroiditis presented to the hospital for evaluation of syncopal episodes associated with dizziness, loss of consciousness and weight loss. She was started three weeks prior to presentation on Escitalopram 10 mg for mild depression. On exam she had orthostatic hypotension, she looked tanned but there was no buccal or palmar pigmentation. Admission blood work showed Na level of (111 mmol/L, n:135-145 mmol/L), Potassium of (5.7 mmol/L, n: 3.5-5 mmol/L), Creatinine of (0.8 mg/dL, n:0.7-1.5 mg/dL). Urine Sodium was (59 mEq/L, n: 20 mEq/L) and Urine osm (306 mOsm/Kg, n:50-1200 mOsm/kg). TSH was normal and 8 AM cortisol level was (6.0 ug/dL, n: 6.0-18.4 ug/dL). Initially Hyponatremia was attributed to SIADH secondary to use of Selective Serotonin Reuptake inhibitors, however her autoimmune comorbidities, orthostatic hypotension and physical exam findings warranted more work up to rule out Adrenal insufficiency. The 250 mcg Cosyntropin Stimulation test was done with baseline cortisol of (4.6 ug/dL, n: 6-18.4 ug/dL) and cortisol at 30 minutes and 60 minutes of (5.2 ug/dL and 5.1 ug/dL respectively) confirming failure to respond to ACTH and diagnosis of adrenal insufficiency. She denied taking exogenous steroids. Later her ACTH came back very high (956 pg/mL, n:7-63 pg/mL), aldosterone was (5.3 ng/dL, n<23 ng/dL), plasma renin activity was high at (20.095 ng/mL/hr, n:0.1-1.3ng/mL/hr) and anti-adrenal antibodies were positive confirming the diagnosis of Addison disease. Patient was started on IV hydrocortisone with slow resolution of hyponatremia and symptoms. She was discharged on maintenance hydrocortisone and fludrocortisone. Given the presence of Hashimoto thyroid disease and Rheumatoid arthritis, patient was diagnosed as having polyglandular autoimmune Syndrome type II. Conclusion: The signs and symptoms of adrenal insufficiency are often nonspecific, resulting in long delays in diagnosis or even misdiagnosis. Hyponatremia is one of the manifestations of adrenal insufficiency which can be inevitably missed or misdiagnosed with syndrome of inappropriate antidiuretic hormone (SIADH) as both can manifest as euvolemic hyponatremia and inappropriate urinary Na concentration. This case demonstrates the importance of thorough investigation of underlying etiologies of patients with symptomatic hyponatremia who are also at risk SIADH secondary to SSRIs use. Presentation: Friday, June 16, 2023

THU226 Pituitary Hyperplasia With Optic Chiasm Compression Secondary To Levothyroxine Non-adherence In An Adolescent Patient

Abstract Disclosure: C. Hawco: None. L. Bursztyn: None. P. Gallego: None. S. Van Uum: None. Background: Pituitary hyperplasia is a rare complication of primary hypothyroidism in pediatric patients. There have been multiple reports of unnecessary surgical procedures for this medically treatable condition. Clinical Case: A 16-year-old female was referred for pituitary enlargement. She had presented to a community hospital following an unwitnessed syncopal event, complicated by retrograde amnesia and headache. At the age of 2 she was diagnosed with primary hypothyroidism during work up for similar syncopal episodes. Past medical and developmental history was otherwise non-contributory. She had a long-standing history of medication non-compliance, and had not taken Levothyroxine during the previous 11 months. On her presentation to hospital, a CT scan revealed pituitary enlargement with a hypodensity suspicious for hemorrhage. Pituitary panel was significant for TSH greater than 1000 (0.51-4.30) mIU/L, free T4 of 4 (13-21) pmol/L and Prolactin 98 ng/mL (&lt25) ng/mL. She was subsequently transferred to our tertiary care pediatric hospital for admission and ongoing care. An MRI of the sella identified a 1.0 x 2.3 x 1.7 cm pituitary mass with suprasellar extension and mass effect on the optic chiasm and nerves. There was no associated hemorrhage. The thyroid gland was diffusely enlarged. Visual acuity was 20/60 in both eyes at the time of hospital admission, compared to 20/20 the previous week at her optometrist. Formal visual field testing was abnormal, but unreliable with no clear defects. She was initiated on Levothyroxine 100 mcg daily and closely monitored for adherence and symptom resolution. After two months on this dose, repeat MRI sella showed a decrease of the pituitary mass to 0.8 x 2.1 x 1.0 cm in size, consistent with a diagnosis of pituitary hyperplasia secondary to untreated primary hypothyroidism. After treatment for 3 months, her visual acuity returned to 20/20 in both eyes with normal visual fields. With ongoing adherence to medical therapy, she remained clinically euthyroid with further decrease in her pituitary size, and normalization of both thyroid indices and prolactin[SV1]. Conclusion: This case is a rare presentation of pituitary hyperplasia in the setting of treatment nonadherence in primary hypothyroidism. It emphasizes the importance of monitoring for signs and symptoms of pituitary enlargement when low or non-adherence for levothyroxine treatment is suspected. The resolution of pituitary enlargement with Levothyroxine treatment also reinforces that this condition is best managed medically, avoiding unnecessary surgical procedures. Reference: (1) Sapkota, S., Karn, M., Sapkota, S. Pituitary hyperplasia in childhood primary hypothyroidism: a review. Childs Nerv Syst. 2021;37;749-762. [SV1] Presentation: Thursday, June 15, 2023

An Unusual Cause of Neck Pain and Headache in Pregnancy.

A previously healthy 21-year-old Caucasian female G1P0 at 32 weeks gestation presented to the ED for an episode of syncope. She also complained of headaches, neck pain, and blurry vision. Physical examination revealed a healthy pregnant female. Neurological examination demonstrated Grade III papilledema but was otherwise unremarkable. CT brain revealed hydrocephalus and intraventricular hemorrhage of unclear etiology MRI of the head was negative for a mass lesion. MRA/MRV of the head was negative, ruling out cavernous sinus thrombosis. Lumbar puncture was bloody but negative for infection. Infectious workup, including HSV, toxoplasmosis, and neurocysticercosis, was negative. An intraventricular drain was placed for hydrocephalus. While in the hospital, she developed sudden left-sided weakness, prompting an emergency C-section. Further workup with CT angio of the brain and neck revealed an arteriovenous malformation (AVM) involving the anterior spinal artery and adjacent venous plexus. Digital subtraction angiography showed a C2-3 pial AVM with a partially thrombosed nidal aneurysm. She was transferred to an outside hospital for embolization. Embolization obliterated the aneurysm, but residual flow remained in the AVM. Blood products are visible on sagittal MRI after embolization. At hospital discharge, her left-sided weakness had resolved, and her neurological examination was normal. The hydrocephalus had resolved.

Renal trauma during a rugby tackle

Rugby-related renal trauma is rare and identification of a young patient with renal trauma secondary to sports who requires observation versus further radiological evaluation in the emergency department (ED) poses a diagnostic challenge. We report a case of a 16-year-old girl who presented to the ED with abdominal pain after being tackled during a game of rugby. Examination revealed tenderness over the right lateral lower ribs and right flank. Blood tests were normal and bedside ultrasound did not show any free intraperitoneal fluid. Urinalysis showed gross hematuria. She was pain-free after analgesia but had a syncopal episode in the ED. A computed tomography (CT) scan of the abdomen and pelvis showed a complex right lower pole renal laceration and she was admitted to the Intensive Care Unit. She remained stable and was discharged. Assessment with urinalysis, hematocrit, and creatinine is required during the evaluation of a patient with suspected renal trauma. CT scan is the imaging modality for the diagnosis and grading of renal injury. Conservative treatment is the mainstay of therapy, but some patients require angioembolization of surgical intervention. Patients must discuss with their physician regarding the optimal timing of return to rugby. Rugby-related renal trauma is rare and poses a challenge for emergency physicians regarding their evaluation and management in the ED. AAST-OIS grading of renal trauma on CT imaging helps guide appropriate management decisions.

Absent Pulmonary Valve in Corrected Tetralogy of Fallot

We present the case of a 24-year-old male patient with a history of correction of tetralogy of Fallot when he was 2. He reports presenting 6 syncopal episodes during the last 6 months. Therefore, a transthoracic color Doppler echocardiogram was performed, reporting right ventricular dilatation, mild global deterioration of the right ventricular systolic function, absent pulmonary valve with severe insufficiency, and free passage. A diagnosis of absent pulmonary valve with severe valvular insufficiency was made. Surgical treatment was performed by placing an aortic bioprosthesis (stentless) No. 25, Medtronic FreestyleTM, in the pulmonary position. The patient evolved favorably and was discharged without complications on the fourth postoperative day. In addition, a brief bibliographic review of the disease is made.

Spiral dissection of the left coronary artery as a rare and serious complication of coronary angiography: a case report

Background: Iatrogenic spiral dissection of the coronary artery is a rare but serious complication of Coronary angiography (CA). CA is a standard imaging method, which is considered as a safe and commonly used.Aim of the study: To demonstrate a rare complication of CA that significantly changed the patient’s outcome.Material and methods: A retrospective review of the procedure and the patient’s follow-up has been performed.Case report: A 56-year-old woman with type two atrial septal defect complicated by heart failure (HF), complaining of a gradual HF worsening and two episodes of syncope was admitted for preoperative assessment. Prior to cardiac surgery an elective CA revealed no stenoses in coronary arteries, however it was complicated by the spiral dissection of the left main coronary artery continuing towards the left anterior descending artery. Immediate percutaneous coronary angioplasty was performed with a good acute angiographic and clinical result. Subsequently, the patient developed a periprocedural inferolateral myocardial infarction and cardiac arrest due to pulseless electrical activity. Cardiopulmonary resuscitation was ineffective.Conclusion: The take home message of the case presented is that even a relatively safe procedure may be complicated and that less invasive imaging modalities should be considered prior to CA.

Cardiovascular—Exercise Related Syncopal Episodes

Cardiovascular—Exercise Related Syncopal Episodes

Acute lymphocytic myocarditis presenting as complete heart block in an adult: a case report

BackgroundComplete heart block (CHB) as a first presentation of acute viral myocarditis is a rare occurrence associated with increased morbidity and mortality. In such cases, an endomyocardial biopsy is recommended to make a clear histological diagnosis aiding to differentiate from other possible conditions such as sarcoiditic myocarditis, giant cell myocarditis, and eosinophilic myocarditis. Insertion of a permanent pacemaker may be considered on a case-to-case basis.Case presentationA previously healthy 21-year-old female presented to the emergency department after having suffered two episodes of syncope on a background of a few days’ history of myalgias, chills, and rigors. Electrocardiogram showed high-grade Mobitz II block with intermittent periods of CHB. A bedside echocardiogram upon admission demonstrated normal biventricular systolic function. Given the patient’s unstable haemodynamic status and lack of obvious reversible causes for the CHB, a permanent dual-chamber pacemaker was inserted urgently. Initial blood investigations indicated an ongoing inflammatory process highlighting the possibility of myocarditis as a cause of the CHB. Therefore, a troponin level was taken and was noted to be elevated confirming the suspicion of myocarditis. The left ventricular ejection fraction (LVEF) decreased over the following days to approximately 20%, clinically resulting in pulmonary oedema and acute shortness of breath. The patient required aggressive intravenous diuresis and anti-heart failure medication. An endomyocardial biopsy (EMB) confirmed the diagnosis of lymphocytic myocarditis. The patient’s condition improved secondary to an improvement in LVEF and resolution of the heart block. A cardiac magnetic resonance (CMR) imaging performed 6 weeks from admission reported an improved LVEF of 51% with no late gadolinium enhancement (LGE). Based on the reassuring CMR findings and the resolution of CHB on follow-up pacemaker checks, it was deemed safe to explant the pacemaker.ConclusionsAcute myocarditis may be complicated with high-degree AV block and cardiogenic shock necessitating close observation in a critical care unit. A permanent pacemaker may provide atrio-ventricular synchrony which helps stabilise the patient’s condition and protect from a prolonged period of heart block. Early myocardial fibrosis on EMB and degree of LGE on CMR are indicators of persistent atrioventricular block. Guideline-directed treatment of heart failure is essential.

Autosomal Recessive Long QT Syndrome: Clinical Aspects and Therapy.

The autosomal recessive (AR) form of Long QT Syndrome (LQTS) is described both associated with deafness known as Jervell and Lange-Nielsen (JLN) syndrome, and without deafness (WD). The aim of the study is to report the characteristics of AR LQTS patients and the efficacy of the therapy. Data of all children with AR LQTS referred to the Bambino Gesù Children's Hospital IRCCS from September 2012 to September 2021were included. Three (30%) patients had compound heterozygosity and 7 (70%) had homozygous variants of the KCNQ1 gene, the latter showing deafness. Four patients (40%) presented aborted sudden cardiac death (aSCD): three with previous episodes of syncope (75%), the other without previous symptoms (16.6% of asymptomatic patients). An episode of aSCD occurred in 2/3 (66.7%) of WD and heterozygous patients, while in 2/7 (28%) JLN and homozygous patients and in 2/2 patients with QTC > 600ms. All patients were treated with Nadolol. In 5 Mexiletine was added, shortening QTc and obtaining the disappearance of the T-wave alternance (TWA) in 3/3. Episodes of aSCD seem to be more frequent in LQTS patients with compound heterozygous variants and WD than in those with JLN and homozygous variants. Episodes of aSCD also appear more frequent in children with syncope or with QTc value > 600ms, even on beta-blocker therapy, than in patients without syncope or with Qtc < 600ms. However, our descriptive results should be confirmed by larger studies. Moreover, Mexiletine addition reduced QTc value and eliminated TWA.

Novel combinations of variations in KCNQ1 were associated with patients with long QT syndrome or Jervell and Lange-Nielsen syndrome

ObjectivesLong QT syndrome (LQTS) is one of the primary causes of sudden cardiac death (SCD) in youth. Studies have identified mutations in ion channel genes as key players in the pathogenesis of LQTS. However, the specific etiology in individual families remains unknown.MethodsThree unrelated Chinese pedigrees diagnosed with LQTS or Jervell and Lange-Nielsen syndrome (JLNS) were recruited clinically. Whole exome sequencing (WES) was performed and further validated by multiplex ligation-dependent probe amplification (MLPA) and Sanger sequencing.ResultsAll of the probands in our study experienced syncope episodes and featured typically prolonged QTc-intervals. Two probands also presented with congenital hearing loss and iron-deficiency anemia and thus were diagnosed with JLNS. A total of five different variants in KCNQ1, encoding a subunit of the voltage-gated potassium channel, were identified in 3 probands. The heterozygous variants, KCNQ1 c.749T > C was responsible for LQTS in Case 1, transmitting in an autosomal dominant pattern. Two patterns of compound heterozygous variants were responsible for JLNS, including a large deletion causing loss of the exon 16 and missense variant c.1663 C > T in Case 2, and splicing variant c.605-2 A > G and frame-shift variant c.1265del in Case 3. To our knowledge, the compound heterozygous mutations containing a large deletion and missense variant were first reported in patients with JLNS.ConclusionOur study expanded the LQTS genetic spectrum, thus favoring disease screening and diagnosis, personalized treatment, and genetic consultation.

Black Esophagus and Recurrence of Duodenal Ulcers: Two Signs of the Same Pathogenic Pathway? A Case Report

Black esophagus or acute esophageal necrosis is characterized by circumferential black discoloration of the distal esophageal mucosa. It is a rare condition with a multifactorial pathogenesis, and its most common clinical presentation is acute upper gastrointestinal bleeding. It usually affects elderly patients with multiple comorbidities and is associated with a high mortality rate. This is a case report of a 90-year-old man with multiple comorbidities, including diabetes mellitus, atrial fibrillation with complete atrioventricular block, and a history of ischemic stroke, who presented to the emergency department for a syncopal episode followed by coffee ground emesis. Thoraco-abdominal computer tomography showed thickening of the distal esophagus and ruled out major complications such as perforation. The following esophagogastroduodenoscopy showed black circumferential necrosis of the mid and distal esophagus. Multiple irregular ulcers with black necrotic areas were also present in the bulb and second duodenal portion. During the hospitalization, the patient was treated with PPI, NPO nutrition, and broad-spectrum antibiotics with benefits. Two months later, the patient returned to the emergency department due to a new episode of hematemesis with endoscopic evidence of esophageal stricture without necrosis and recurrence of duodenal ulcers. After a few days, the patient died due to worsening of the underlying comorbidities. A black esophagus is associated with duodenal ulcers, which may recur and are possibly due to a common ischemic origin. In this case report, we explore the potential link between black esophagus and duodenal ulcers, discussing the underlying mechanisms and relevant literature supporting this association.

Validation of clinical-radiological scores for prognosis of mortality in acute pulmonary embolism

IntroductionAcute pulmonary embolism (APE) is a hazardous disorder with a high mortality. Combination of clinical, radiological, and serological parameters can improve risk stratification of APE. Most of the proposed combined scores were not validated in independent cohorts. Our aim was to validate the proposed clinical-radiological scores for prognosis of 7- and 30-day mortality in APE.Materials and methodsOur sample comprised 531 patients with APE, mean age 64.8 ± 15.6 years, 221 (41.6%) females and 310 (58.4%) males. The following parameters were collected: Age and sex of the patients, mortality within the observation time of 30 days, simplified pulmonary embolism severity index (sPESI), pH troponin level (pg/ml), minimal systolic and diastolic blood pressures (mmHg), heart rate, O2 saturation, episodes of syncope, and need for vasopressors. On CT pulmonary angiography (CTPA), short axis ratio right ventricle/left ventricle (RV/LV), and reflux of contrast medium into the inferior vena cava were obtained. The following clinical-radiological scores were calculated: BOVA score, pulmonary embolism mortality score (PEMS), European Society of Cardiology (ESC) score, Kumamaru score, and Calgary acute pulmonary embolism (CAPE) score.ResultsOverall, 31 patients (5.8%) died within seven and 64 patients (12%) within 30 days. All scores showed high negative prognostic values ranging from 89.0 to 99.0%. PEMS and CAPE score demonstrated the highest specificity for 7-day mortality (93.4% and 85.0%), PEMS and BOVA for 30-day mortality (94.2% and 90.4%). The highest sensitivity was observed for ESC 2019 (96.8% and 95.3%). Kumamaru and CAPE scores had low sensitivity. All scores had low positive and high negative predictive values.ConclusionFor prognosis of 7- and 30-day mortality in APE, PEMS score has the highest specificity. ESC 2019 shows the highest sensitivity. All scores had low positive and high negative predictive values.

Woman With Syncopal Episode and Seizure-like Activity.

Woman With Syncopal Episode and Seizure-like Activity.

An unusual cause of life-threatening episodic syncope: cellular angiofibroma in the right ventricular outflow tract.

An unusual cause of life-threatening episodic syncope: cellular angiofibroma in the right ventricular outflow tract.

Paroxysmal atrioventricular block in a mixed‐breed dog

AbstractAn 11‐year‐old female mixed‐breed dog was presented with syncopal episodes occurring up to 10 times a day for 3 months. The owner reported events lasting for approximately 15 s, during which the dog would fall into lateral recumbency, have muscle tremors and show intense salivation. After the event, the animal was disorientated for a few seconds before full recovery. A surface electrocardiogram was obtained, during which an episode of syncope occurred, with a paroxysmal atrioventricular block lasting 10.5 s. The event was characterised as an intrinsic pause‐dependent paroxysmal atrioventricular block associated with cardiogenic syncope type 1E. The dog received aminophylline 10 mg/kg every 8 hours and the frequency of syncopal episodes decreased until it died of non‐cardiac causes 3 months later. There is little information on paroxysmal atrioventricular blocks in dogs, and further electrocardiographic event characterisation may the influence choice of therapy in individual cases.

Association Between Syncope Trigger Type and Risk of Subsequent Life-Threatening Events in Patients With Long QT Syndrome

Syncope is the most powerful predictor for subsequent life-threatening events (LTEs) in patients with congenital long QT syndrome (LQTS). Whether distinct syncope triggers are associated with differential subsequent risk of LTEs is unknown. To evaluate the association between adrenergic (AD)- and nonadrenergic (non-AD)-triggered syncopal events and the risk of subsequent LTEs in patients with LQT types 1 to 3 (LQT1-3). This retrospective cohort study included data from 5 international LQTS registries (Rochester, New York; the Mayo Clinic, Rochester, Minnesota; Israel, the Netherlands, and Japan). The study population comprised 2938 patients with genetically confirmed LQT1, LQT2, or LQT3 stemming from a single LQTS-causative variant. Patients were enrolled from July 1979 to July 2021. Syncope by AD and non-AD triggers. The primary end point was the first occurrence of an LTE. Multivariate Cox regression was used to determine the association of AD- or non-AD-triggered syncope on the risk of subsequent LTE by genotype. Separate analysis was performed in patients with β-blockers. A total of 2938 patients were included (mean [SD] age at enrollment, 29 [7] years; 1645 [56%] female). In 1331 patients with LQT1, a first syncope occurred in 365 (27%) and was induced mostly with AD triggers (243 [67%]). Syncope preceded 43 subsequent LTEs (68%). Syncopal episodes associated with AD triggers were associated with the highest risk of subsequent LTE (hazard ratio [HR], 7.61; 95% CI, 4.18-14.20; P < .001), whereas the risk associated with syncopal events due to non-AD triggers was statistically nonsignificant (HR, 1.50; 95% CI, 0.21-4.77; P = .97). In 1106 patients with LQT2, a first syncope occurred in 283 (26%) and was associated with AD and non-AD triggers in 106 (37%) and 177 (63%), respectively. Syncope preceded 55 LTEs (56%). Both AD- and non-AD-triggered syncope were associated with a greater than 3-fold increased risk of subsequent LTE (HR, 3.07; 95% CI, 1.66-5.67; P ≤ .001 and HR, 3.45, 95% CI, 1.96-6.06; P ≤ .001, respectively). In contrast, in 501 patients with LQT3, LTE was preceded by a syncopal episode in 7 (12%). In patients with LQT1 and LQT2, treatment with β-blockers following a syncopal event was associated with a significant reduction in the risk of subsequent LTEs. The rate of breakthrough events during treatment with β-blockers was significantly higher among those treated with selective agents vs nonselective agents. In this study, trigger-specific syncope in LQTS patients was associated with differential risk of subsequent LTE and response to β-blocker therapy.

It never happens, until it happens

An 86-year-old female patient was treated at home after having suffered a syncopal episode preceded by intermittent dyspnea in the previous weeks. Upon admission, the electrocardiogram showed Mobitz 2 second-degree AV (atrioventricular) block. Our patient suffered from systemic hypertension and chronic open-angle glaucoma, treated, respectively, with losartan 100 mg/hydrochlorthiazise 25 mg every 24 h and timolol 0.5% two times a day (introduced three weeks before after being assessed by ophthalmology service at another hospital center). Dyspnea and electrocardiographic blockage signs stopped once ocular beta blockers (timolol) were discontinued. Ocular topical administration is usually the preferred route for drug supply in ophthalmology and especially in glaucoma treatment, but it is not devoid of interactions and adverse effects. The following clinical case describes how the use of topical beta blockers for the treatment of glaucoma may be at the origin of systemic beta-blockade in our patient, a not so common, yet described situation.

The Fatal Interplay between Stress Induced Cardiomyopathy, Arrhythmia and Cardiogenic Shock

A 59-year-old man presents to the hospital following a syncopal episode after a low-speed car accident without visible injuries. He was diagnosed with stress cardiomyopathy and severe triple-vessel coronary artery disease. The case was complicated by complete heart block that culminated in refractory cardiogenic shock. Literature and current approach are reviewed.