Syncopal patients without prodromes exhibit a diverse pattern of adenosine release during head-up tilt test

Background/Introduction

In a significant proportion of patients with neurally-mediated syncope (NMS), the mechanism of syncope remains largely undetermined. Adenosine has been proposed as a central humoral factor in various forms of NMS: high Adenosine Plasma Levels (ADP) are encountered in patients with vasovagal syncope (VVS), low ADP in non-prodromes syncope (NPS), while ADP in patients with situational syncope SS are less well determined.

Purpose

We sought to assess ADP in patients with different clinical forms of syncope, with an emphasis on the presence or absence of prodromal symptoms, as well as the relation between ADP and the outcomes of Head-Up Tilt Table Test (HUTT) and Adenosine test (ADT).

Methods

Patients with different clinical types of NMS (n=124), i.e., VVS, NPS, or SS, were investigated using a standard protocol including HUTT and ADT. During HUTT, ADP was measured in the supine position, at table tilting, and in syncope.

Results

Baseline ADP did not differ among groups. ADP at syncope were higher in NPS compared to VVS (1.55±1.29 vs 0.16±0.05 μM, p=0.03) and SS (0.15±0.05 μM, p=0.02). In NPS, ADP increased from the supine position to the time of syncope (0.47±0.25 to 1.55±1.29 μM, p=0.04). In VVS, ADP increased only from the supine to the tilt position (0.23±0.04 to 0.35±0.10 μMu, p=0.02), while in SS ADP did not change in any stage of HUTT. SS was associated with cardioinhibitory HUTT (OR 3.40, 95% CI 1.05 to 9.56, p=0.04) and positive ADT (OR 4.22, 95% CI 1.47 to 11.46, p=0.012).

Conclusion(s)

A distinct pattern of ADP increase is noted during HUTT in NPS, suggesting that an excessive increase of ADP may play the key role in triggering this type of clinical presentation of syncope independently of the baseline ADP. Cardioinhibition prevails in patients with SS without clear adenosine involvement. Such observations contribute to an enhanced understanding of the pathophysiology of different clinical forms of syncope which may offer the possibility to tailor the management approach appropriately.

Funding Acknowledgement

Type of funding sources: None.

First insights from patients presenting with long/post-COVID syndrome in primary care: an exploratory report

Background

Following the global pandemic of coronavirus disease 2019 (COVID-19), the long COVID or post-COVID syndrome refers to a relatively complex novel clinical entity. We conducted this study to assess the primary epidemiological features, main symptoms, and comorbidities probably related to this syndrome in patients referred to our long/post-COVID primary care unit during the initial months of its operation.

Methods and Material

This single-center prospective observational study was conducted between April 2022 and December 2022 and enrolled 71 patients (33 men, 38 women) who were examined due to persisting symptoms after recovering from COVID-19 infection, with the mean time of the first visit estimated at 3.12 ± 2.41 months from their acute COVID-19 illness. A thorough medical history, clinical examination, laboratory, and any other tests were performed on all patients when necessary.

Results

The most common symptoms of long/post-COVID reported were fatigue (63.4 %), a persistent cough (45.1 %), stress manifestations (42.3 %), arthralgia or myalgia (33.8 %), tachycardia (32.4 %), depression manifestations (29.6 %), exertional dyspnea (28.2 %), and sleep disorders (25.4 %). Hypertension (in about 40 %) and the presence of five or more symptoms during the acute COVID-19 illness (in approximately 52 %) could be regarded as factors increasing the long/post-COVID appearance. The long/post-COVID syndrome affects even patients not experiencing severe COVID-19 illness. Unvaccinated patients are at higher risk of severe COVID-19 (p =0.014), higher risk of hospitalization (p =0.002), and in higher need of respiratory support with high flow (p =0.017) when compared to vaccinated ones. Hospitalized patients appear to be older than outpatients (59 ± 12.42 vs 52.78 ± 11.48 years of age; p =0.032.

Conclusion

The long/post-COVID syndrome is an established clinical entity, and several clinical features, symptoms, and patient profiles have to be assessed from the initial medical contact in primary care to exclude early any other clinical conditions and offer guided therapeutic strategies to those patients. HIPPOKRATIA 2022, 26 (4):138-142.

Adenosine plasma levels and adenosine receptor levels determine the outcome of adenosine test and head-up tilt test in syncopal patients with a normal heart

Background/Introduction

The neurohumoral profile underlying the manifestation of reflex syncope remains incompletely understood. Adenosine plasma (ADP) and adenosine receptor (ADR) levels may differentiate the outcomes of head-up tilt table test (HUTT) and adenosine test (ADT) but their role in the diagnostic evaluation of patients with syncope has yet to be determined.

Purpose

We sought to assess the ADP and ADR levels in patients without structural heart disease who underwent HUTT and ADT tests as part of the diagnostic workup of syncope. We specifically investigated differences in the outcomes of the HUTT and ADT tests as well as to the ADP levels during HUTT.

Methods

HUTT and ADT were performed as per the standard protocols. ADT was considered positive in the event of asystole >6 seconds or heart block for >10 seconds after intravenous Adenosine 0.15 mg/kg administration in the supine position. ADP levels were assessed at three timepoints during the HUTT: at baseline (supine), immediately after bed tilt and, in cases of a positive HUTT, at the time of syncope. Patients were categorized in quintiles of very low, low, intermediate, high and very high baseline ADP levels. We also assessed the A2A ADR levels of monocytes.

Results

We prospectively analyzed 124 patients (71 women, age 46.78±21.01 years). ADT was positive in 12.9% of patients and HUTT in 44.4% of patients. Patients with very low baseline ADP levels (lowest quintile) more frequently presented with a positive ADT (odds ratio [OR] 4.08, 95% Confidence Interval [CI] 1.40 to 13.13, p<0.05). Baseline ADP did not differ between patients with positive and negative HUTT. However, patients with vasodepressor response to HUTT exhibited increase in ADP from baseline to bed tilt (0.33±1.03 vs. 0.42±1.14 ppm/Um/L, p<0.05) and in syncope (0.70±1.89, P<0.05), while no difference was noted in patients with cardioinhibitory or mixed response. Patients with positive ADT and negative HUTT had higher ADR levels (221.5±88.56 MFI) as compared to patients with negative ADT and positive HUTT (59.78±83.65 MFI, p<0.05) and to patients with positive ADT and HUTT (33.29±35.77 MFI, p<0.05). Within patients with positive HUTT, those with onset of syncope in the Isoprenaline provocation phase (>20 min) had lower ADR levels (80.88±238.98 vs 89.43±96.08 MFI, p<0.05).

Conclusion(s)

Baseline ADP levels are related to the outcome of ADT while an ADP increase immediately after bed tilt and in syncope is evident in vasodepressor response to HUTT. Higher ADR levels are related to positive ADT and negative HUTT. Lower ADR levels are associated with more delayed onset of syncope during HUTT. ADP and ADR levels warrant further investigation as they may characterize a subset of patients with specific responses to ADT and HUTT and may be implicated in the pathophysiology of reflex syncope.

Funding Acknowledgement

Type of funding sources: None.

Baseline adenosine plasma levels indicate differential response to adenosine test and head-up tilt test in syncopal patients

Background/Introduction

Head-up tilt table test (HUTT) and Adenosine test (ADT) can be useful in the diagnostic evaluation of syncope. Adenosine plasma (ADP) and Adenosine receptor (ADR) levels may differentiate the outcomes of HUTT and ADT but their precise role in the risk stratification of patients with syncope remains elusive.

Purpose

We sought to assess the ADP and ADR levels in patients without structural heart disease who underwent HUTT and ADT tests as part of the diagnostic workup of syncope. We specifically investigated differences in the outcomes of the HUTT and ADT tests as well as to the ADP levels during HUTT according to the baseline ADP levels.

Methods

HUTT and ADT were performed as per the standard protocols. ADT was considered positive in the event of asystole >6 seconds or heart block for >10 seconds after intravenous Adenosine 0.15 mg/kg administration in the supine position. ADP levels (ppm/Um/L) were assessed at three timepoints during the HUTT: at baseline (supine), immediately after bed tilt and, in cases of a positive HUTT, at the time of syncope. Patients were categorized in terciles of low, intermediate and high baseline ADP levels. We also assessed the A2A ADR levels of monocytes.

Results

We prospectively analyzed 106 patients (62 women, age 46.87±20.63 years). ADT was positive in 14.2% of patients and HUTT in 47.2% of patients. Females were more likely to have low ADP levels (odds ratio [OR] 2.70, 95% Confidence Interval [CI] 1.04 to 6.94, p<0.05). Patients with low baseline ADP levels showed a trend for positive ADT (OR 3.15, 95% CI 1.05 to 10.85, p=0.07), while patients with high baseline ADP levels showed a trend for negative HUTT (OR 2.35, 95% CI 0.94 to 5.90, p=0.075). Within patients with positive HUTT, those with low baseline ADP levels, showed an increase in ADP in the tilt phase (0.063 vs 0.027 ppm/Um/L, p<0.05) but not at the time of syncope (0.045 ppm/Um/L) while those with intermediate baseline ADP levels showed an increase in ADP in the tilt phase (0.16 vs 0.095 ppm/Um/L, p<0.05) which persisted during syncope (0.18 ppm/Um/L, p<0.05). Patients with high baseline ADP levels did not exhibit differences in ADP during positive HUTT. Higher baseline ADP levels were associated with smaller increases in the tilt phase (Pearson's r −0.621, p<0.001). ADR levels in patients with positive HUTT correlated positively with baseline ADP levels (Pearson's r 0.878, p<0.001).

Conclusion(s)

Baseline ADP levels may be related to the outcome of ADT and HUTT. ADP increases during HUTT except for patients with high baseline ADP. ADP and ADR levels warrant further investigation as they may characterize a subset of patients with specific responses to HUTT and may be implicated in the pathophysiology of reflex syncope.

Funding Acknowledgement

Type of funding source: None

Early-onset and recurrent reflex syncope is associated with left ventricular diastolic filling and left atrial function properties

Background/Introduction

The effects of the left atrial and ventricular function in the pathophysiology of reflex syncope remain elusive. Head-up tilt table test (HUTT) is frequently used in the diagnostic workup of patients with syncope, but the outcomes of HUTT have not been attributed to any anatomical or functional cardiac characteristics.

Purpose

We sought to assess the effects of anatomical and functional echocardiographic features of the left atrium and the left ventricle at rest in the clinical presentation of syncope and the outcomes of HUTT.

Methods

We investigated patients with a history of syncope and symptoms suggestive of reflex syncope who underwent HUTT. Specific echocardiographic indices of left cardiac morphology and function were assessed at rest. The patients were divided into two groups, those who presented with syncopal episodes at age <35 years (group A) and those who presented with syncopal episodes at age >35 years (group B).

Results

In 119 patients (age 46.75±21.17 years, 69 women), patients in group A exhibited a higher chance for numerous (>3) syncopal episodes (odds ratio [OR] 3.4, 95% Confidence Interval [CI] 1.41 to 7.93, p<0.05). Group A showed also a trend for positive HUTT (OR 1.99, 95% CI 0.97 to 4.23, p=0.08). In patients with positive HUTT, Group A had higher E-wave velocity (0.83 vs 0.65 m/sec, p<0.05), lower A-wave velocity (0.60 vs 0.75 m/sec, p<0.05), higher E/A ratio (1.54 vs 1.00, p<0.05), higher e' wave velocity (0.16 vs 0.10 m/sec, p<0.05) and lower E/e' (5.64 vs 7.85, p<0.05). Also, patients in group A exhibited lower left atrial volumes (min 9.88 vs 16.21 ml, p<0.05, max 30.42 vs 44.89 ml, p<0.05), higher left atrial strain reservoir (40.56 vs 32.42%, p<0.05) and higher left atrial strain booster (25.94 vs 18.06%, p<0.05).

Conclusion(s)

Patients with a younger age of onset and recurrent syncopal episodes manifest smaller dimensions of the left atrium with distinct patterns of diastolic performance and better reservoir and booster function. These findings may indicate a more pronounced susceptibility of this group of patients to preload reduction, thereby triggering the mechanism of reflex syncope.

Funding Acknowledgement

Type of funding source: None

P6573Adenosine plasma levels may determine tilt table test outcome in syncopal patients with prodromal symptoms

Background/Introduction

Head-up tilt table test (HUTT) and Adenosine test (ADT) are tools frequently used in the diagnostic workup of syncope. It has been suggested that patient responses to HUTT and ADT can be related to the plasma levels of Adenosine (ADPL) and Adenosine receptors (ADR). However, the exact type of association and the role of (ADPL) and ADR levels in the risk stratification and management of patients with syncope has not yet been clarified.

Purpose

We sought to assess the ADPL and ADR levels in patients without structural heart disease who underwent HUTT and ADT tests as part of the diagnostic workup of syncope. We specifically investigated differences with regards to the presence of a history of prodromal symptoms.

Methods

HUTT and ADT were performed as per the standard protocols. ADT was considered positive in the event of asystole >6 seconds or heart block for >10 seconds after intravenous Adenosine administration in a supine position at a dose of 0.15 mg/kg. ADPL were assessed at three timepoints during the HUTT: in the supine position, immediately after bed tilt and, in cases of a positive test, at the time of syncope. Furthermore, we assessed the A2A ADR of monocytes in the study patients.

Results

We prospectively analyzed 77 patients (48 women, age 47.05±21.10 years). ADT was positive in 16.7% of patients and HUTT in 49.4% of patients. ADPL in the supine position did not differ between patients with negative vs. positive ADT but showed a significant correlation with the body mass index (p=0.002). There was a trend for reduced ADPL at the tilt phase in patients with positive HUTT (0.32±0.89 vs. 0.42±0.77 ppm/Um/L, p=0.09). Of all patients, 60 (77.9%, 41 women, age 46.80±21.83 years) had reported a history of prodromal symptoms at syncope. In the subset of patients with prodromal symptoms, the ADL at the tilt phase were lower in patients with positive vs. negative HUTT (0.15±0.23 vs. 0.51±0.89, p<0.05). ADR did not differ among groups but showed a significant correlation with the ADL during syncope in patients with prodromal symptoms (p<0.05).

Conclusion(s)

Patients with prodromal symptoms and a positive HUTT demonstrate reduced ADPL at the tilt phase of HUTT preceding syncope. In these patients, ADPL in syncope correlate with the ADR. Adenosine plasma levels and receptors warrant further investigation and may predict the response to HUTT thereby contributing to the diagnostic evaluation and risk stratification of patients with syncope.

Bleomycin cardiotoxicity during chemotherapy for an ovarian germ cell tumor

INTRODUCTION

Platinum-based chemotherapeutic regimens, including BEP (bleomycin, etoposide, cisplatin) represent the standard of care, first line therapy in non-epithelial ovarian tumours. Cardiovascular toxicity is a rare adverse effect of bleomycin.

CASE REPORT

A 41-year-old woman with ovarian granulosa tumor, treated with first line BEP chemotherapy experienced chest discomfort rapidly progressing to severe precordial pain during bleomycin infusion. The infusion was stopped and electrocardiographic changes indicative of myocardial ischemia were revealed. Anti-anginal and anti-thrombotic treatment was introduced. Cardiac enzymes were not elevated and echocardiographic findings showed no wall motion abnormalities. Twenty four hours after the episode the elctrocardiographic changes insisted and chemotherapy was decided to be continued, excluding bleomycin, with no symptom recurrence.

DISCUSSION

Cardiovascular complications pose a rare but potential fatal adverse effect of BEP chemotherapy and should be carefully addressed, especially in patients with additional cardiovascular risk factors. Physicians dealing with bleomycin-based therapies may find this knowledge useful for a more comprehensive evaluation of chest pain syndromes in those patients.