Telemedicine in Cardiology: Modern Technologies to Improve Cardiovascular Patients' Outcomes-A Narrative Review.

The registration of physical signals has long been an important part of cardiological diagnostics. Current technology makes it possible to send large amounts of data to remote locations. Solutions that enable diagnosis and treatment without direct contact with patients are of enormous value, especially during the COVID-19 outbreak, as the elderly require special protection. The most important examples of telemonitoring in cardiology include the use of implanted devices such as pacemakers and defibrillators, as well as wearable sensors and data processing units. The arrythmia detection and monitoring patients with heart failure are the best studied in the clinical setting, although in many instances we still lack clear evidence of benefits of remote approaches vs. standard care. Monitoring for ischemia is less well studied. It is clear however that the economic and organizational gains of telemonitoring for healthcare systems are substantial. Both patients and healthcare professionals have expressed an enormous demand for the further development of such technologies. In addition to these subjects, in this paper we also describe the safety concerns associated with transmitting and storing potentially sensitive personal data.

The P wave dispersion-one pixel, one millisecond.

The electrophysiological activity of the heart is recorded and presented in form of electrocardiogram (ECG). In 1998 the concept of P wave dispersion as the risk factor for atrial fibrillation (AF) recurrence was introduced. It was calculated as the difference between the longest and the shortest P wave. The aim of our study is to prove that the P wave dispersion is an artifact of low accuracy in P wave measurement. The study included 186 patients (78M 108F) aged 59.7 ± 12.9 years, undergoing various electrophysiological procedures. The P wave was measured twice: first, at the paper speed of 50 mm/s, enhancement 8× (standard - imprecise) and the second time at 200 mm/s, 64-256× (precise). The imprecise measurement method resulted in different duration of all P wave parameters in comparison with precise measurement. The difference between Δ P max and Δ P min indicated a higher value for the latter parameter. It was indicated that the imprecise P wave dispersion value correlated most significantly with the maximal P wave duration, which was measured in a similar way. In contrast with the imprecise measurement method, the minimal and maximal durations of the P waves, being measured accurately, were almost identical. Using precise methodology, the P wave dispersion reaches negligible values and tends to zero. The measurements of the P wave have to be precise to assure the highest scientific and medical sincerity. The highest clinical value is related to the P wave duration.

Analysis of COVID-19 Incidence and Protective Potential of Persisting IgG Class Antibodies against SARS-CoV-2 Infection in Hospital Staff in Poland.

The immune responses to both SARS-CoV-2 infection and vaccines are of key importance in prevention efforts. In April and May 2020, 703 study participants tested for COVID-19 by PCR tests were registered. In June and July 2020, they were examined for the presence of SARS-CoV-2 S1/S2 IgG. From October 2020 to January 2021, those among the study population with COVID-19 confirmed by PCR tests were registered, and the same group of participants was invited to be examined again for the presence of SARS-CoV-2 antibodies. In June 2020, antibodies were detected in only 88% of those who had PCR-confirmed COVID-19 in April-May 2020, which suggests that a significant proportion of persons in the Polish population do not produce antibodies after contact with SARS-CoV-2 antigens or rapidly lose them and reach levels below the lab detection limit. The levels of IgG class anti-SARS-CoV-2 antibodies were significantly lower among people who previously had COVID-19 than for those who had received COVID-19 vaccination, which confirms the high immunogenicity of the vaccines against COVID-19 in the Polish population. The study confirms that a detectable level of IgG class anti-SARS-CoV-2 antibodies cannot be considered a reliable marker of the presence and strength of COVID-19 immunity preventing individuals from acquiring SARS-CoV-2 infection.

ST-segment depression in atrioventricular nodal reentrant tachycardia: Important finding or just an artifact?

BACKGROUND: The ST segment is component of the QRS-T complex located between the QRS and the T wave. ST segment changes during tachycardia with narrow QRS mainly takes the form of ST segment depression. This phenomenon is often observed in young healthy people for whom an ischemic background is unlikely. MATERIALS AND METHODS: The study included 104 patients (71 women and 33 men) with paroxysmal narrow QRS complex tachycardia. In all patients electrophysiological study was performed and the diagnosis of atrioventricular nodal reentrant tachycardia was established. The arrhythmogenic substrate was then eliminated successfully by subsequent ablation using radiofrequency energy which confirmed the diagnosis, all patients had measured QRS components - QR, RS and RJ during the tachycardia and during the sinusrhythm. All of the measurements were done in lead V5. RESULTS: The difference RJ-QR during tachycardia and sinus rhythm correlated negatively with tachycardia cycle length (R = 0.356, P = .001), first slowly, then rapidly reaching the cycle value of about 300 ms, then it decreases, stabilizing at the cycle level of about 270. By separating the RJ-QR in tachycardia and in the sinus rhythm from the tachycardia cycle, we can see that the correlation described in this point is largely due to the correlation between the heart rate and RJ-QR length in tachycardia. CONCLUSIONS: In patients with atrioventricular nodal reentrant tachycardia, there is a significant ST-segment depression during tachycardia episodes and the degree of this change is related to tachycardia cycle length. The most probable explanation of the ST-segment depression is the overlap of the QRS complex on the preceded T wave. This phenomenon is also influenced by some intrinsic properties of the individual electrocardiogram. It is possible to rule out ischemic origin of the presented ST segment change.

Co-toxicity of Endotoxin and Indoxyl Sulfate, Gut-Derived Bacterial Metabolites, to Vascular Endothelial Cells in Coronary Arterial Disease Accompanied by Gut Dysbiosis.

Gut dysbiosis, alongside a high-fat diet and cigarette smoking, is considered one of the factors promoting coronary arterial disease (CAD) development. The present study aimed to research whether gut dysbiosis can increase bacterial metabolites concentration in the blood of CAD patients and what impact these metabolites can exert on endothelial cells. The gut microbiomes of 15 age-matched CAD patients and healthy controls were analyzed by 16S rRNA sequencing analysis. The in vitro impact of LPS and indoxyl sulfate at concentrations present in patients' sera on endothelial cells was investigated. 16S rRNA sequencing analysis revealed gut dysbiosis in CAD patients, further confirmed by elevated LPS and indoxyl sulfate levels in patients' sera. CAD was associated with depletion of Bacteroidetes and Alistipes. LPS and indoxyl sulfate demonstrated co-toxicity to endothelial cells inducing reactive oxygen species, E-selectin, and monocyte chemoattractant protein-1 (MCP-1) production. Moreover, both of these metabolites promoted thrombogenicity of endothelial cells confirmed by monocyte adherence. The co-toxicity of LPS and indoxyl sulfate was associated with harmful effects on endothelial cells, strongly suggesting that gut dysbiosis-associated increased intestinal permeability can initiate or promote endothelial inflammation and atherosclerosis progression.

Can the in-hospital mortality rate in patients with ST-elevation myocardial infarctions be lowered any further?

BACKGROUND: A myocardial infarction is a specific clinical condition characterized by a relatively high acute mortality rate. Earlier reperfusion results in a smaller infarct size and a lower mortality rate. OBJECTIVES: To assess the in-hospital mortality in patients with ST-elevation myocardial infarction (STEMI) regarding patients' characteristics, and the mechanisms behind the deterioration in hemodynamic and clinical status, in order to assess the possibility of preventing this type of death. MATERIAL AND METHODS: A group of 106 patients aged 64.5 ±11.3 years was divided into 2 groups: patients who died while hospitalized (group I; n = 5) and patients who survived while hospitalized for STEMI (group II; n = 101). Primary coronary intervention was performed in all individuals, with direct stent implantation in all but 1 patient. In all patients the standard medication was started or continued, depending on the patient's status. The demographic and selected clinical and biochemical parameters were compared between the study groups. RESULTS: The patients in group I were significantly older than the survivors (76.2 ±12.7 compared to 64.0 ±11.0 years; p < 0.05). The group with fatal myocardial infarction had a lower left ventricular ejection fraction (LVEF) (31.7 ±12.8% compared to 60.4 ±11.0%; p < 0.05) and a higher maximal serum troponin level (973.6 ±1121.8 ng/mL compared to 453.2 ±924.2 ng/mL; p < 0.05). Interestingly, among the patients who died, the pain-to-balloon time was significantly shorter than in the myocardial infarction survivors (84 ±48 min compared to 342 ±504 min; p < 0.05). CONCLUSIONS: The development of the medical care system has made invasive procedures available, improving outcomes in patients with acute myocardial infarction. This form of treatment is likely optimized to such an extent that any changes in the time before intervention will not substantially improve mortality rates.

ST-segment depression in atrioventricular nodal reentrant tachycardia: Preliminary results.

BACKGROUND: The ST-segment is part of the electrocardiogram and physiologically, it forms an isoelectric line. The ST-segment depression is often observed in young, healthy people with paroxysmal tachycardia with narrow QRS complexes. In this group of patients, the 'mysterious tachycardia-induced ST-segment depression', 'subendocardial myocardial ischemia' and other not fully understood terms are used to explain this phenomenon. OBJECTIVES: To assess the presence and possible mechanisms of ST-segment depression during atrioventricular nodal reentrant tachycardia (AVNRT) in patients undergoing radiofrequency (RF) ablation of the underlying arrhythmia. MATERIAL AND METHODS: The study included 50 patients (35 women and 15 men) aged about 49 years with clinically relevant paroxysmal narrow QRS complex tachycardia. During electrophysiological study (EPS), all patients had measured QRS components - QR, RS and RJ during the tachycardia and during the sinus rhythm. All of the measurements were done in lead V5. RESULTS: There was a statistically significant difference in cycle length during sinus rhythm and tachycardia (707.0 ±137.8 ms compared to 327.5 ±29.1 ms, p = 0.000), the RJ component (0.819 ±0.381 mV compared to 0.878 ±0.376 mV, p = 0.003) and the difference RJ-QR (0.081 ±0.083 mV compared to 0.163 ±0.108 mV, p = 0.000). The differences in RS and QR components during sinus rhythm and tachycardia did not reach the statistical significance. The difference RJ-QR during tachycardia correlated negatively with tachycardia cycle length (R = -0.39, p = 0.0049). The tachycardia cycle length correlated positively with the age of the studied patients (R = 0.28, p = 0.043). CONCLUSION: In patients with AVNRT, there is a ST-segment depression during the episodes of tachycardia and the degree of this change is related to tachycardia cycle length. The most probable explanation of the ST-segment depression is the overlap of the QRS complex on the preceded T wave. Some intrinsic properties of individual electrocardiogram (ECG) also influence this phenomenon. The ischemic origin of the presented ST-segment change can be excluded.

P wave duration in paroxysmal and persistent atrial fibrillation.

BACKGROUND: Functional and structural changes in the atrial muscle constitute a substrate for atrial fibrillation (AF). The pathological changes in the left atrium decrease the conduction velocity and result in prolongation of the P wave duration. OBJECTIVES: To assess the duration of the P wave in patients with AF in different clinical presentations of arrhythmia. MATERIAL AND METHODS: The study group consisted of 119 patients diagnosed with AF: 57 women and 62 men, aged 65.3 ±9.4 years. There were 65 patients with paroxysmal AF and 54 with persistent AF. In this group, electrical cardioversion was performed. The P wave duration was measured using an electrophysiological system in all leads at a paper speed of 200 mm/s. RESULTS: The patients did not differ in terms of age, gender or comorbidities. The patients with persistent AF had longer P wave duration (159.9 ±22.3 ms compared to 144.6 ±17.2 ms; p < 0.001) and higher glucose concentration (119.4 ±33.4 mg/dL compared to 108.0 ±24.6 mg/dL; p = 0.015). These results were not influenced by the anti-arrhythmic treatment. CONCLUSIONS: Persistent AF shows a longer P wave duration than the paroxysmal AF, independent of age, gender and anti-arrhythmic medication. The prolongation of the P wave related to persistent arrhythmia should force physicians to restore the sinus rhythm earlier in order to more successfully maintain it in the long term.

The true nature of P wave dispersion.

BACKGROUND: The electrophysiological activity of the heart is recorded and presented in form of electrocardiography (ECG). In 1998, the concept of P wave dispersion as the risk factor for atrial fibrillation (AF) recurrence was introduced. It was calculated as the difference between the longest and the shortest P wave. OBJECTIVES: To prove that the P wave dispersion is an artifact of low accuracy in P wave measurement. MATERIAL AND METHODS: The study included 104 patients (48 women, 56 men), aged 63 ±14 years, undergoing various electrophysiological procedures. The P wave was measured twice - firstly at the paper speed of 50 mm/s, enhancement ×8 (standard - imprecise), and secondly at 200 mm/s, ×64-256 (precise). RESULTS: The imprecise measurement method resulted in different duration of all P wave parameters in comparison with precise measurement. The longest P wave duration (Pmax) measured imprecisely was 105.1 ±22.1, the Pmax measured precisely was 134.0 ±21.3 (p < 0.001). The P dispersion measured imprecisely was 44.1 ±16.8 and the P dispersion measured precisely was 2.8 ±3.4 (p < 0.0001). The correlation between imprecise Pmax and imprecise Pmin was r = 0.664 (p < 0.05). The correlation between imprecise Pmax and imprecise P wave dispersion was r = 0.612 (p < 0.05). The correlation between precise Pmax and Pmin was almost 1.0 (r = 0.987, p < 0.05). CONCLUSIONS: The P wave dispersion does not exist. The measurements of the P wave have to be precise to assure the highest scientific and medical sincerity. The highest clinical value is related to the P wave duration.