[The anti-arrhythmic effect of L-carnitine in subjects with ischemic cardiopathy].
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Adult↗
Biomedical subjects
N Alessandri
Publications and source records attributed to N Alessandri.
[Chronobiological pattern size of cardiac rhythm (author's transl)].
The basic knowledge of statistical methods in chronobiology are exposed, for the analysis of chronobiological features of cardiac rhythm. The cosinor's method, with definition of chronobiological parameters (acrophase, mesor and amplitude) allows a microscopic approach to study of biological rhythms. The AA. relate some chronobiological studies: a) on heart rate in normal subjects and in patients with myocardial infarction (MI); b) on premature ventricular beats in MI; c) on atrial and ventricular rates in complete AV block. These results demonstrate that there is an evident circadian rhythmicity for all analyzed parameters. The AA. analyse the physiological and clinical meaning of the chronobiological approach to cardiac rhythm for the chronopharmacological and pathophysiological studies and suggests the implications in pathology of adaptation to shift work.
Circadian Rhythm↗
Catheter-related right-sided endocarditis in bone marrow transplant recipients.
Bone marrow transplant recipients are at increased risk of severe central venous catheter-related septicemias that may be complicated by endocardial infection. In view of this, we prospectively evaluated 141 consecutive patients receiving allogeneic or autologous bone marrow infusion. Seven (5%) of 141 patients developed eight episodes of a clinical syndrome compatible with catheter-related right-sided infective endocarditis; this diagnosis was confirmed at autopsy in two patients who died. Staphylococcus epidermidis was the most frequent isolate (four cases). Other offending pathogens were, in one case each, Enterococcus faecalis, Corynebacterium jeikeium, Pseudomonas alcaligenes, and Achromobacter xylosoxidans plus Candida species. Three- to 7-week courses of antibacterial therapy were associated with a favorable outcome in six of the seven cases. Infective endocarditis may be a complication of the use of central venous catheters and should be actively sought in septicemic bone marrow transplant recipients.
Adolescent↗
Thrombus formation in the left atrial appendage in the course of atrial fibrillation.
BACKGROUND: Thromboembolism in patients with nonvalvular atrial fibrillation is secondary to emboli arising from atrial cavities, particularly left atrial appendage. Stroke Prevention Atrial Fibrillation (SPAF) III study showed washing flow, left appendage ejection fraction, natural echocontrast, and left appendage volume and morphology, as risk parameters of thromboembolism. METHODS: The authors examined 69 patients by transesophageal echocardiography, subdividing them into 3 groups: 26 patients in sinus rhythm in Group A (Gr.A), 22 patients in atrial fibrillation without thrombi in the left atrial appendage in Group B (Gr.B), 21 patients with tromboembolism and with thrombus in the left atrial appendage (Gr.C). RESULTS: Atrial volume in sinus rhythm (SR) patients (41.9 +/- 23.4 cm3) was lower than the one in Gr.B (86.2 +/- 47.9 cm3, p < 0.001) and Gr.C (78.6 +/- 28.5 cm3, p < 0.01), whereas no difference was found between Gr.B and Gr.C (86.2 vs. 78.6 cm3; p > 0.05). No difference was found between Gr.A and Gr.B left atrial appendage fraction (31.8% versus 29.1%, p > 0.05), whereas it was found related to Gr.C (31.8% versus 15.4% p < 0.01). Flow velocity within left atrial appendage was significantly higher in Gr.A in relation to the other two groups (p < 0.001); flow velocity in Gr.B was lower than in Gr.A but higher than in Gr.C and in all cases such differences were statistically significant (p < 0.001). Gr.A flow duration was approximately twice as much compared to the one in Gr.B (616.8 +/- 94.1 msec vs. 483.3 +/- 172.6 msec, p < 0.01), whereas it was approximately four times higher compared to the one in Gr.C (616.8 +/- 94.1 msec vs. 165.7 +/- 53.7 msec; p < 0.001). Such duration, if related to the corresponding cardiac cycle, indicates the percentage of time during which blood flows through a cycle within the left atrial appendage; this value is about 85% of cardiac cycle in Gr.A, while it is 65% in Gr.B (p < 0.01) and about 21% in Gr.C (p < 0.001). CONCLUSIONS: Such results add a new parameter to the ones suggested in the SPAF III study for the evaluation of TE risk, that is flow duration measurement within the left atrial appendage, and its ratio to the cardiac cycle. The availability to measure this parameter, by recording the transesophageal pulse wave sample volume positioned in the atrial appendage, makes the evaluation of TE risk more reliable.
Atrial Appendage↗
Diastolic mitral regurgitation: a borderline case in cardiovascular physiology.
BACKGROUND: Mitral regurgitation during diastole in 5 subjects, of whom 4 affected by cardiovascular disease and 1 healthy competitive athlete, was the aim of this work. The 4 patients are respectively affected by: 1st case: arterial hypertension, dyslipidemia and III degree AV block in NYHA class II heart failure (HF); 2nd case: NYHA III HF, prosthetic biologic aortic valve dysfunction; 3th case: NYHA III HF, ischemic dilated cardiomyopathy; 4th case: ischemic dilated cardiomyopathy waiting for heart transplantation. METHODS AND RESULTS: The above 4 patients showed, on transthoracic echocardiogram, mitral diastolic regurgitation. The authors deem as caused, in agreement with the literature, both by an atrio-ventricular pressure gradient inversion during long-lasting diastoles (III degree atrioventricular block, blocked atrial systole, aortic valve regurgitation), and by an inadequate ventricular remodelling/distensibility. The 5th case deals with a healthy highly trained competitive athlete who, at the fitness checkup, showed mitral diastolic regurgitation. The study was also extended to two healthy groups of subjects, in order to rule out mitral regurgitation during the diastolic interval of the cardiac cycle. CONCLUSIONS: Such finding, after an accurate and critical analysis, led the authors to assume it may deal with a borderline physiological condition.
Adult↗
Prominent crista terminalis mimicking a right atrial mixoma: cardiac magnetic resonance aspects.
A 68-year-old woman came to our observation with a clinical history of isolated systolic hypertension poorly controlled by the combination of ramipril 5 mg and hydrochlorothiazide 12.5 mg o.d. The ECG showed sinus rhythm with heart rate of 68 beats per minute and signs of left ventricular hypertrophy without strain. Further investigation included an echocardiogram that showed normal left and right cavities and normal cardiac valves. At the level of the posterior wall of the right atrial (RA) an apparent smooth, bean-like tumor, having a thin pedicle, was identified as a RA mixoma. Cardiac MRI was requested and showed in two sequential slices a muscular ridge, identified as a prominent crista terminalis. Some para-physiological structures sited in the RA may have the appearance of tumors, as crista terminalis, Eustachian valve extending into the RA chambers and Chiari network. The multiplain projections of MRI allow the cardiologist to identify the presence of intracardiac masses and to make a differential diagnosis between neoplasms and variant anatomic structures.
Aged↗
A case of non-conducted atrial bigeminy simulating a second-degree atrioventricular block. A holter ECG diagnosis.
A 82-years-old man, symptomatic for fatigue and lypothymia, was referred to our centre in order to evaluate the opportunity of a permanent pacemaker insertion. A 12-lead ECG was described as a Mobitz type II second-degree atrioventricular block with 2:1 conduction. This surface ECG revealed some sinus beats with normal AV conduction, everyone followed by a bizarre, non-conducted P' wave, inscripted in the previous T wave. The Holter ECG showed a sinus rhythm with a mean rate of 70 beats/minute: during the night and at 06:39 pm of the following day, ECG strip showed some sinus beats, everyone followed by an atrial non-conducted ectopic beat, characterized by prematurity and abnormal shape (P' wave), that appears as a small deformation on the preceding T wave. At the beginning and the end of the strip we can estimate respectively 9 and 4 sinus beats, that represent the normal rhythm of this patient. So, it is possible to compare the normal P-P interval (P-P = 0.84 sec) to the shorter P-P' interval (P-P = 0.40 sec) and make the correct diagnosis of non-conducted atrial bigeminy simulating a second-degree AV block with 2:1 conduction.
Aged↗
[Dynamic electrocardiography. A new approach to chronobiology].
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Adult↗