Atrial fibrillation activates platelets and coagulation in a time-dependent manner: a study in patients with paroxysmal atrial fibrillation.

OBJECTIVES: To determine whether atrial fibrillation (AF) alone affects the fibrinocoagulation system, we examined the relation between fibrinocoagulation activity and duration of AF in patients with paroxysmal AF (PAF). BACKGROUND: Patients with chronic AF are at higher risk for stroke and a hypercoagulative state. It is not clear whether this hypercoagulative state is attributable to AF alone or to the underlying disease. There are no reports on the fibrinocoagulation properties in PAF. METHODS: Fibrinocoagulation variables in 21 patients with PAF were measured during AF and 7 days after recovery of sinus rhythm. There were positive correlations between the duration of AF and beta-thromboglobulin, platelet factor 4, thrombin-antithrombin III complex and fibrinogen. These variables increased significantly 12 h after the occurrence of PAF; thus, patients were classified into two groups according to the duration of PAF: PAF-I group (< 12 h, n = 10), PAF-II group (> or = 12 h, n = 11). Nine age-matched, healthy subjects formed the control group. RESULTS: Levels of beta-thromboglobulin and platelet factor 4 were significantly higher (p < 0.001) by two-way repeated measures analysis of variance (ANOVA), and thrombin-antithrombin III complex and fibrinogen levels tended to be but were not significantly higher (p = 0.06, ANOVA), in the PAF-II group than in the PAF-I group. There were no significant differences between groups in activated partial thromboplastin time, D-dimer or plasmin inhibitor complex. CONCLUSIONS: These results indicate that AF itself enhances platelet aggregation and coagulation, which are influenced by the duration of AF. The acceleration of platelet activity and coagulability occurred 12 h after the occurrence of AF.

Simple 13C-urea breath test with infra-red spectrophotometer.

When mass spectrophotometric analysis is used for the 13C-urea breath test to assess H. pylori infection, it is costly, complicated, and time-consuming. To overcome these disadvantages, we utilized an infra-red spectrophotometer as a substitute for the mass spectrophotometer. A total of 153 patients (181 tests) analyzed with peptic ulcers or non-ulcer dyspepsia were investigated. Breath samples were collected 15 min after ingestion of 13C-urea (100 mg in 30 ml water). An infra-red spectrophotometer was used to determine the concentration of 13CO2 in the expirate. The 13CO2/12CO2 ratio was also measured by mass spectrophotometry to compare results with those of infra-red spectrophotometric analysis. Direct detection of H. pylori was qualified in biopsy specimens. Of the 181 biopsies, 138 were positive for H. pylori infection and 43 were negative. With the urea breath test, the mean value in the positive group was significantly higher than that in the negative group (0.062 +/- 0.044 vs 0.011 +/- 0.014, respectively). The cut-off level, 0.01, was determined as delta 13C atom %. The sensitivity of infra-red spectrophotometry was 97.8% (135/138) and specificity was 74.4% (32/43). There was an extremely high coefficient of correlation (r = 0.996) between mass and infra-red photometric analysis. Infra-red spectrometry appears to have great potential not only for diagnosing H. pylori infection but also for assessing treatment results. Its advantages include technical simplicity, cost-effectiveness, and high accuracy.

Infective endocarditis caused by an indigenous bacterium (Gemella morbillorum).

A case of infective endocarditis (IE) caused by a rare pathogen, Gemella morbillorum, is presented. Because of persistent low-grade fever after dental treatment, the patient was given oral antibiotics. Whereas he was diagnosed as having aortic regurgitation by a cardiologist, and IE was not suggested unfortunately. After long-term chemotherapy over five months, he was aware of nocturnal dyspnea and Gemella morbillorum was detected by blood culture. Then, he was treated with intravenous administration of Penicillin-G, and underwent surgical operation for valve replacement. No cases of IE due to this organism have been reported in Japan.

Fourteen-year survival in a case of ventricular septal perforation after myocardial infarction.

We treated a case of ventricular septal perforation (VSP) who survived for 14 years after myocardial infarction. Nine years after the onset of myocardial infarction, an apparent cardiac murmur was discovered by chance, and following further examination, the patient was diagnosed as having VSP. The patient is still in the NYHA functional class I, and requiring no surgical treatment. In general, the prognosis of myocardial infarction complicated with VSP is so poor that there have only been 14 reported cases of long survival without surgical treatment. Among these patients, only 2 survived for more than 10 years. The present case is extremely rare, and evidently is the longest living survivor with this condition yet reported.

Sudden death during Holter electrocardiogram monitoring in a patient with variant angina.

We report a case of sudden death due to variant angina during Holter electrocardiogram (ECG) monitoring. The patient, a 60-year-old man, had been aware of chest discomfort lasting less than one minute at midnight 2 days earlier. Because variant angina or arrhythmia was suspected, Holter ECG monitoring was performed. The patient spent a whole day without a recurrence of chest pain before going to bed, but at midnight he developed sudden chest pain, and died immediately after taking a sublingual tablet of isosorbide-dinitrite. Analysis of the Holter ECG revealed ventricular fibrillation after several ventricular premature beats following ST-segment elevation in both the CM5 and NASA leads. This case shows that sudden death from variant angina may occur within a few days after the first onset, and also highlights whether priority should be given to making a definite diagnosis or giving treatment when variant angina is strongly suspected.

Smooth muscle cell proliferation in the arterial intima after stretch injury: relationship between the severity of stretching and intima hyperplasia in New Zealand white rabbits.

We examined histologically whether the severity of arterial stretch injury is related to the degree of subsequent intimal hyperplasia. In six male New Zealand White rabbits, the common carotid artery was hyperextended with a 3F Fogarty balloon catheter. Two weeks later, no proliferative change was evident in the intima in the most hyperextended portion. Paradoxically, however, intimal hyperplasia due to smooth muscle cell proliferation was observed in the moderately extended portions. The intimal hyperplasia appeared to be exacerbated where the arterial stretching was more severe. It is concluded that the severity of arterial stretch injury is closely related to the intimal proliferation of smooth muscle cells.

[Two cases of mitral restenosis occurring eight years after percutaneous balloon mitral commissurotomy (PTMC)].

A 63-year-old man and a 49-year-old man who underwent PTMC eight years before were admitted in our hospital because of regurgitation and restenosis of the mitral valve. Both of them had ulcer like lesion on the anterior leaflet near the commissure of the mitral valve. These changes were made by PTMC and likely caused thrombosis. Long-term follow up data of PTMC is essential to chose the correct operative method for treating mitral stenosis.

Effect of atrial fibrillation on the fibrino-coagulation system--study in patients with paroxysmal atrial fibrillation.

To clarify the effect of atrial fibrillation (AF) on the fibrino-coagulation system, fibrino-coagulation parameters in the paroxysmal period of AF were determined in 13 patients with paroxysmal atrial fibrillation (PAF) and compared with those in the non-paroxysmal period of AF, and with those in normal subjects. Estimated titers of hemoglobin and hematocrit in the paroxysmal period of AF were significantly higher than those in the non-paroxysmal period and also higher than those in normal subjects. The activated partial thromboplastin time in the paroxysmal period was also longer than that in the non-paroxysmal period of AF or in normal subjects. However, other estimated parameters, such as prothrombin time, fibrinogen, thrombin-antithrombin III, beta-thromboglobulin, platelet factor 4, D-dimer and plasmin inhibitor complex, did not show any significant deviation. These results conflict with those of previous reports which indicated that the fibrino-coagulation system was enhanced in cases of chronic AF. Our results suggest that there is no significant activation of the fibrino-coagulation system, except for obvious hemoconcentration, within the first few hours after the onset of PAF. Thus, in terms of the properties of blood coagulation, thromboembolism is preventable if antiarrhythmic therapy is administered within several hours after the onset of PAF.

Chaotic musical murmur in aortic regurgitation.

We report an interesting case of aortic regurgitation. Phonocardiographically, the shape of the diastolic musical murmur in this case changed in each cardiac cycle despite being in sinus rhythm, in the same posture and in the same breathing phase. Experimentally, we were able to obtain a similar noise pattern using an artificial respirator and a hemispherical silicone membrane. We concluded that the irregular and chaotic change in the shape of the diastolic musical murmur in the present case occurred due to irregular swaying of the non-coronary cusp under the influence of the Venturi effect owing to a regurgitant jet stream.

Tensile force of pacing lead extraction. A comparison between tined type and screw-in type.

Three months after implantation of endocardial pacing leads in 10 mongrel dogs, the tensile forces needed to remove 5 tined type and 5 screw-in type leads were compared experimentally. Mean maximum tensile force was 291 +/- 174 g with the screw-in type and 1174 +/- 369 g with the tined type (p < 0.01). Histopathologically, no changes suggesting any myocardial damage due to lead extraction were recognized in cases where screw-in type leads were used. These results support the clinical feasibility of safe and easy manual retraction of infected pacing leads of the screw-in type.

Isolated levocardia associated with absence of inferior vena cava, lobulated spleen and sick sinus syndrome. A case report.

We evaluated a 68-year-old male patient with isolated levocardia without intracardiac anomaly. The patient's condition was complicated by the absence of the inferior vena cava, a lobulated spleen and sick sinus syndrome. Isolated levocardia without intracardiac anomaly is very rare and only 25 cases of this disease have been reported, to our knowledge. In general, it is accepted that cardiac rhythm disorder is frequently observed in cases of isolated levocardia and/or absence of inferior vena cava. However, there are few cases of isolated levocardia without intracardiac anomaly complicated by the absence of the inferior vena cava, a lobulated spleen and apparent sick sinus syndrome.

A case of myocardial infarction showing extensive precordial ST elevation induced by second diagonal branch occlusion.

We observed a case of acute myocardial infarction induced by second diagonal branch occlusion. Electrocardiogram (ECG) on admission showed ST elevation in leads I, aVL and V2-6. Since emergency coronary angiography disclosed complete occlusion of the second diagonal branch, intra-coronary thrombolysis (ICT) was performed, superselectively. Transient coronary reperfusion was obtained, however, reocclusion occurred after several minutes. Rescue percutaneous transluminal coronary angioplasty (PTCA) was then performed immediately and blood flow was improved to TIMI grade 2. During these processes, the ST-segment on the ECG changed in leads I, aVL and V2-6 always corresponding to the blood flow of the second diagonal branch. We have not seen a report hitherto in which occlusion of only the second diagonal branch could be a cause of extensive anterior infarction-like ECG changes. Although the mechanism of ECG changes in this patient cannot be clearly explained by conventional concepts, we report this case because it is considered to be very rare.

Pitfalls of intervention therapy in a patient with anomalous origin of the right coronary artery from the left sinus of Valsalva associated with organic stenosis.

A 64-year-old man visited our hospital with a complaint of exertional chest discomfort. Exercise electrocardiography revealed ST segment depression in the V4-V6 leads, and exercise thallium myocardial scintigraphy demonstrated myocardial ischemia in the area of the right coronary artery, suggesting effort angina. Diagnostic coronary angiography revealed an anomalous origin of the right coronary artery from the left sinus of Valsalva and 90% organic stenosis at the proximal portion. We performed percutaneous transluminal coronary angioplasty (PTCA), but repeat PTCA was required 3 months later because of restenosis. Follow-up angiography 1 year later showed regression of the stenotic lesion to less than 50% diameter compared with the data obtained 3 months after the second PTCA. However, exercise 99mtechnetium-tetrofosmin myocardial scintigraphy disclosed obvious myocardial ischemia in the inferior region. These results suggested that the myocardial ischemia in this particular patient was caused not only by the organic stenosis but also by the anatomic anomaly which might reduce coronary blood flow during exercise. Such patients should be followed up cautiously with much more sophisticated methodology.

Mechanisms for improvement of cardiac performance by nifedipine in an acute mitral regurgitation in dogs.

To elucidate the mechanisms of the beneficial hemodynamic action of nifedipine in congestive heart failure, the systolic and diastolic hemodynamic parameters were evaluated for 30 min after sublingual administration of 20 mg of nifedipine in 12 dogs with acute mitral regurgitation (group 1) and in 5 dogs without mitral regurgitation (group 2, sham operation group). An additional 6 dogs with mitral regurgitation were followed for 30 min without nifedipine (group 3). Nifedipine lowered both arterial pressure and systemic vascular resistance, increased coronary blood flow and stroke volume significantly in both groups 1 and 2. The left ventricular developed tension was increased by nifedipine only in group 1, probably due to the geometric changes in the expanded left ventricle in failure, secondary to left ventricular preload and afterload reduction. Nifedipine had no effects on ventricular relaxation properties in this study. This study suggests that the mechanisms responsible for the improvement of cardiac performance induced by nifedipine in heart failure caused by an acute mitral regurgitation are essentially a reduction in left ventricular afterload and an increase in left ventricular contractility secondary to afterload reduction.

Hemodynamic effects of intravenous administration of olprinone hydrochloride on experimental pulmonary hypertension.

To examine acute effects of olprinone hydrochloride (CAS 106730-54-0, Coretec) on pulmonary hypertension, hypoxic pulmonary hypertension was produced in 6 adult Beagle dogs. Using this pulmonary hypertension model, single intravenous bolus injections of olprinone at doses of 10, 30 and 100 micrograms/kg were administered at 5-min intervals and hemodynamic parameters were evaluated. Heart rate increased at doses of 30 and 100 micrograms/kg, but did not change at a dose of 10 micrograms/kg. Mean aortic pressure, mean pulmonary arterial pressure, pulmonary vascular resistance and systemic vascular resistance and right ventricular stroke work index did not change at doses of 10 and 30 micrograms/kg, but they decreased significantly at a dose of 100 micrograms/kg. On the other hand, cardiac index and the first derivative value of the left ventricular pressure did not show significant change at all doses. These results indicate the vasodilating effects on peripheral and pulmonary vessels in hypoxic model at high doses of olprinone. Its application in right heart failure accompanied by pulmonary hypertension therefore is expected to yield promising results.

Experimental His-bundle pacing: histopathological and electrophysiological examination.

His-bundle pacing gives a more physiological ventricular contraction in comparison to right ventricular apical pacing. However the problems of lead fixation and stability of long-term His-bundle pacing are yet unsolved. We used six adult beagles, in which a screw-in lead was anchored in the His-bundle region for observation of the pacing conditions and histopathologic changes of the conduction system over the course of 2 months. In the results, a satisfactory fixation was obtained using a conventional screw-in lead and no histological influence on the conduction system was observed. The pacing threshold at the time of implantation was 1.15 +/- 0.69 V (3.23 +/- 3.08 mA) in the pulse width of 0.5 ms. R wave amplitude, the impedance and slew rate were 7.28 +/- 2.04 mV, 409 +/- 102 Ohm, and 0.65 +/- 0.41 V/s, respectively. Two months later, these parameters changed to 2.83 +/- 1.06 V (10.4 +/- 5.71 mA), 5.63 +/- 1.62 mV, 310 +/- 71.3 Ohm, and 0.49 +/- 0.22 V/s, respectively. These results suggest the feasibility of clinical application of permanent His-bundle pacing.